U.S. patent application number 11/822441 was filed with the patent office on 2008-01-10 for ester compounds and their preparation, polymers, resist compositions and patterning process.
This patent application is currently assigned to Shin-Etsu Chemical Co., Ltd.. Invention is credited to Takeshi Kinsho, Masaki Ohashi, Takeru Watanabe.
Application Number | 20080008965 11/822441 |
Document ID | / |
Family ID | 38919496 |
Filed Date | 2008-01-10 |
United States Patent
Application |
20080008965 |
Kind Code |
A1 |
Ohashi; Masaki ; et
al. |
January 10, 2008 |
Ester compounds and their preparation, polymers, resist
compositions and patterning process
Abstract
Novel ester compounds having formulae (1) to (4) wherein A.sup.1
is a polymerizable functional group having a carbon-carbon double
bond, A.sup.2 is oxygen, methylene or ethylene, R.sup.1 is a
monovalent hydrocarbon group, R.sup.2 is H or a monovalent
hydrocarbon group, any pair of R.sup.1 and/or R.sup.2 may form an
aliphatic hydrocarbon ring, R.sup.3 is a monovalent hydrocarbon
group, and n is 0 to 6 are polymerizable into polymers. Resist
compositions comprising the polymers as a base resin are thermally
stable and sensitive to high-energy radiation, have excellent
sensitivity and resolution, and lend themselves to micropatterning
with electron beam or deep-UV. ##STR00001##
Inventors: |
Ohashi; Masaki; (Joetsu-shi,
JP) ; Kinsho; Takeshi; (Joetsu-shi, JP) ;
Watanabe; Takeru; (Joetsu-shi, JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
Shin-Etsu Chemical Co.,
Ltd.
|
Family ID: |
38919496 |
Appl. No.: |
11/822441 |
Filed: |
July 5, 2007 |
Current U.S.
Class: |
430/280.1 ;
430/296; 430/330; 528/365; 528/402; 528/417; 549/331; 549/459;
549/463; 549/475; 549/477; 549/478; 560/122; 560/127; 560/128;
560/179; 562/512 |
Current CPC
Class: |
C08F 20/26 20130101;
C08F 20/28 20130101; G03F 7/0046 20130101; G03F 7/0395 20130101;
C07D 307/77 20130101; C07D 307/20 20130101; G03F 7/0397 20130101;
Y10S 430/111 20130101; C07D 309/10 20130101; C08F 222/06 20130101;
C08F 232/04 20130101 |
Class at
Publication: |
430/280.1 ;
430/296; 430/330; 528/365; 528/402; 528/417; 549/331; 549/459;
549/463; 549/475; 549/477; 549/478; 560/122; 560/127; 560/128;
560/179; 562/512 |
International
Class: |
G03C 1/79 20060101
G03C001/79; C07C 53/00 20060101 C07C053/00; C07C 69/66 20060101
C07C069/66; C07C 69/74 20060101 C07C069/74; C07D 307/00 20060101
C07D307/00; G03C 5/38 20060101 G03C005/38; C07D 307/02 20060101
C07D307/02; C07D 311/96 20060101 C07D311/96; C08G 59/42 20060101
C08G059/42 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 6, 2006 |
JP |
2006-186298 |
Claims
1. A polymerizable ester compound having any one of the following
general formulae (1) to (4): ##STR00097## wherein A.sup.1 is a
polymerizable functional group having a carbon-carbon double bond,
A.sup.2 is an oxygen atom, methylene or ethylene group, R.sup.1 is
each independently a straight, branched or cyclic monovalent
hydrocarbon group of 1 to 10 carbon atoms, R.sup.2 is each
independently a hydrogen atom or a straight, branched or cyclic
monovalent hydrocarbon group of 1 to 10 carbon atoms, or a
combination of R.sup.1, a combination of R.sup.2, or a combination
of R.sup.1 and R.sup.2 may bond together to form an aliphatic
hydrocarbon ring with some carbon atoms in the oxygen heterocycle
to which they are attached, and in that event, each of R.sup.1 and
R.sup.2 is a straight, branched or cyclic alkylene group of 1 to 10
carbon atoms, R.sup.3 is each independently a straight, branched or
cyclic monovalent hydrocarbon group of 1 to 10 carbon atoms, or a
combination of R.sup.3 may bond together to form an aliphatic
hydrocarbon ring with some carbon atoms in the ring to which they
are attached, and in that event, each of R.sup.3 is a straight,
branched or cyclic alkylene group of 1 to 10 carbon atoms, and n is
an integer of 0 to 6.
2. The ester compound of claim 1, having any one of the following
general formulae (5) to (8): ##STR00098## wherein A.sup.1, R.sup.1,
R.sup.2, R.sup.3 and n are as defined above, and R.sup.4 is
hydrogen, fluorine, methyl or trifluoromethyl.
3. The ester compound of claim 1, having any one of the following
general formulae (9) to (12): ##STR00099## wherein A.sup.2,
R.sup.1, R.sup.2, R.sup.3, and n are as defined above, R.sup.4 is
hydrogen, fluorine, methyl or trifluoromethyl, and k is 0 or 1.
4. A method for preparing a polymerizable ester compound having the
general formula (1) or (2), comprising the steps of: reacting an
imine compound having the general formula (21) with a compound
having the general formula (22) or (23) to form a
hydroxyl-containing imine compound having the general formula (24)
or (25), subjecting the hydroxyl-containing imine compound to acid
hydrolysis to form a hemiacetal compound having the general formula
(17) or (18), and acylating the hemiacetal compound to form a
polymerizable ester compound having the general formula (1) or (2),
##STR00100## ##STR00101## wherein A.sup.1 is a polymerizable
functional group having a carbon-carbon double bond, R.sup.1 is
each independently a straight, branched or cyclic monovalent
hydrocarbon group of 1 to 10 carbon atoms, R.sup.2 is each
independently a hydrogen atom or a straight, branched or cyclic
monovalent hydrocarbon group of 1 to 10 carbon atoms, or a
combination of R.sup.1, a combination of R.sup.2, or a combination
of R.sup.1 and R.sup.2 may bond together to form an aliphatic
hydrocarbon ring with some carbon atoms in the oxygen heterocycle
to which they are attached, and in that event, each of R.sup.1 and
R.sup.2 is a straight, branched or cyclic alkylene group of 1 to 10
carbon atoms, and R.sup.5 is each independently a straight,
branched or cyclic monovalent hydrocarbon group of 1 to 10 carbon
atoms, or a combination of R.sup.5 may bond together to form an
aliphatic hydrocarbon ring with the carbon atom to which they are
attached.
5. A polymer comprising at least recurring units derived from the
polymerizable ester compound of claim 1, and having a weight
average molecular weight of 2,000 to 100,000.
6. The polymer of claim 5, further comprising recurring units of at
least one type selected from the following general formula
(R.sup.1): ##STR00102## wherein R.sup.001 is hydrogen, fluorine,
methyl, trifluoromethyl or CH.sub.2CO.sub.2R.sup.003, R.sup.002 is
hydrogen, methyl or CO.sub.2R.sup.003, R.sup.003 is a straight,
branched or cyclic C.sub.1-C.sub.15 alkyl group, R.sup.004 is
hydrogen or a monovalent hydrocarbon group of 1 to 15 carbon atoms
having at least one group selected from among fluorinated
substituent groups, carboxyl, hydroxyl and cyano groups, at least
one of R.sup.005 to R.sup.008 is a carboxyl group or a monovalent
hydrocarbon group of 1 to 15 carbon atoms having at least one group
selected from among fluorinated substituent groups, carboxyl,
hydroxyl and cyano groups while the remaining of R.sup.005 to
R.sup.008 are each independently hydrogen or straight, branched or
cyclic C.sub.1-C.sub.15 alkyl groups, or two of R.sup.005 to
R.sup.008 may bond together to form an aliphatic hydrocarbon ring
with the carbon atom(s) to which they are attached, and in that
event, at least one of R.sup.005 to R.sup.008 is a divalent
hydrocarbon group of 1 to 15 carbon atoms having at least one group
selected from fluorinated substituent groups, carboxyl, hydroxyl
and cyano groups while the remaining of R.sup.005 to R.sup.008 are
each independently single bonds, hydrogen atoms or straight,
branched or cyclic C.sub.1-C.sub.15 alkyl groups; R.sup.009 is a
monovalent hydrocarbon group of 3 to 15 carbon atoms containing a
--CO.sub.2-- partial structure, at least one of R.sup.010 to
R.sup.013 is a monovalent hydrocarbon group of 2 to 15 carbon atoms
containing a --CO.sub.2-- partial structure while the remaining of
R.sup.010 to R.sup.013 are each independently hydrogen atoms or
straight, branched or cyclic C.sub.1-C.sub.15 alkyl groups, or two
of R.sup.010 to R.sup.013 may bond together to form an aliphatic
hydrocarbon ring with the carbon atom(s) to which they are
attached, and in that event, at least one of R.sup.010 to R.sup.013
is a divalent hydrocarbon group of 1 to 15 carbon atoms having a
--CO.sub.2-- partial structure while the remaining of R.sup.010 to
R.sup.013 are each independently single bonds, hydrogen atoms or
straight, branched or cyclic C.sub.1-C.sub.15 alkyl groups;
R.sup.014 is a polycyclic hydrocarbon group having 7 to 15 carbon
atoms or an alkyl group containing such a polycyclic hydrocarbon
group, R.sup.015 is an acid labile group, X is CH.sub.2 or an
oxygen atom, and k is 0 or 1.
7. The polymer of claim 5, comprising recurring units derived from
the polymerizable ester compound of any one of formulae (1) to (4)
in a molar fraction of at least 5%.
8. A resist composition comprising the polymer of claim 5.
9. A resist composition comprising (A) the polymer of claim 5, (B)
an acid generator, and (C) an organic solvent.
10. A resist composition comprising (A) the polymer of claim 5, (B)
an acid generator, (C) an organic solvent, and (D) a sensitivity
regulator.
11. A process for forming a pattern, comprising the steps of
applying the resist composition of claim 8 onto a substrate to form
a resist coating; heat treating the coating and exposing to
high-energy radiation or electron beam through a photomask; and
optionally heat treating the exposed coating and developing with a
developer.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This non-provisional application claims priority under 35
U.S.C. .sctn.119(a) on Patent Application No. 2006-186298 filed in
Japan on Jul. 6, 2006, the entire contents of which are hereby
incorporated by reference.
TECHNICAL FIELD
[0002] This invention relates to (1) a novel ester compound, (2) a
polymer comprising units derived from the ester compound which is
blended as a base resin to formulate a chemically amplified resist
composition suitable in the micropatterning technology, (3) a
resist composition comprising the polymer, and (4) a patterning
process using the resist composition.
BACKGROUND OF THE INVENTION
[0003] While a number of recent efforts are being made to achieve a
finer pattern rule in the drive for higher integration and
operating speeds in LSI devices, deep-ultraviolet lithography is
thought to hold particular promise as the next generation in
microfabrication technology. In particular, photolithography using
a KrF or ArF excimer laser as the light source is strongly desired
to reach the practical level as the micropatterning technique
capable of achieving a feature size of 0.3 .mu.m or less.
[0004] For resist materials for use with a KrF excimer laser,
polyhydroxystyrene having a practical level of transmittance and
etching resistance is, in fact, a standard base resin. For resist
materials for use with an ArF excimer laser, polyacrylic or
polymethacrylic acid derivatives and polymers comprising
cycloaliphatic compounds in the backbone are under investigation.
In either case, the basic concept is that some or all of alkali
soluble sites of alkali soluble resin are protected with acid
labile groups. The overall performance of resist material is
adjusted by a choice from among a variety of acid labile
groups.
[0005] Exemplary acid labile groups include tert-butoxycarbonyl
(JP-B 2-27660), tert-butyl (JP-A 62-115440 and J. Photopolym. Sci.
Technol. 7 [3], 507 (1994)), 2-tetrahydropyranyl (JP-A 2-80515 and
JP-A 5-88367), and 1-ethoxyethyl (JP-A 2-19847 and JP-A 4-215661).
While it is desired to achieve a finer pattern rule, none of these
acid labile groups are deemed to exert satisfactory
performance.
[0006] More particularly, tert-butoxycarbonyl and tert-butyl are
extremely less reactive with acids so that a substantial quantity
of energy radiation must be irradiated to generate a sufficient
amount of acid in order to establish a difference in rate of
dissolution before and after exposure. If a photoacid generator of
the strong acid type is used, the exposure can be reduced to a
relatively low level because reaction can proceed with a small
amount of acid generated. However, in this event, the deactivation
of the generated acid by air-borne basic substances has a
relatively large influence, giving rise to such problems as a T-top
pattern. On the other hand, 2-tetrahydropyranyl and 1-ethoxyethyl
are so reactive with acids that with only the acid generated by
exposure, elimination reaction may randomly proceed without wait
until heat treatment, resulting in substantial dimensional changes
between exposure and heat treatment/development. Where these groups
are used as protective groups for carboxylic acid, they have a low
inhibiting effect to alkali dissolution, resulting in a high rate
of dissolution in unexposed areas and film thinning during
development. If highly substituted polymers are used to avoid such
inconvenience, there results an extreme drop of heat resistance.
These resins fail to provide a difference in rate of dissolution
before and after exposure, resulting in resist materials having a
very low resolution.
[0007] In case where 2-adamantyloxymethyl is used as the protective
group for carboxylic acid, its performance is good with respect to
sensitivity and resolution, but such a protective group of
methylene acetal type gives off formaldehyde having a low boiling
point after deprotection, leaving the risk of lens contamination by
outgassing. While a further reduction of pattern feature size is
being demanded, there is a need to have a resist material which is
not only satisfactory in sensitivity, resolution, and etch
resistance, but also minimized in outgassing.
DISCLOSURE OF THE INVENTION
[0008] Therefore, an object of the present invention is to provide
(1) a novel ester compound having a good acid-decomposition ability
and high thermal stability and a method for preparing the same, (2)
a polymer which is blended as a base resin to formulate a resist
composition having a high sensitivity and resolution as well as
minimized outgassing, (3) a resist composition comprising the
polymer as a base resin, and (4) a patterning process using the
resist composition.
[0009] It has been found that ester compounds of the general
formulae (1) to (4), shown below, can be prepared in high yields by
a simple method to be described later; that polymers obtained using
the ester compounds have high transparency at the exposure
wavelength of an excimer laser; that resist compositions comprising
the polymers as the base resin have a high sensitivity, high
resolution and high thermal stability; and that these resist
compositions lend themselves to precise micropatterning.
[0010] In one aspect, the invention provides a polymerizable ester
compound having any one of the following general formulae (1) to
(4).
##STR00002##
Herein A.sup.1 is a polymerizable functional group having a
carbon-carbon double bond, A.sup.2 is an oxygen atom, methylene or
ethylene group, R.sup.1 is each independently a straight, branched
or cyclic monovalent hydrocarbon group of 1 to 10 carbon atoms,
R.sup.2 is each independently a hydrogen atom or a straight,
branched or cyclic monovalent hydrocarbon group of 1 to 10 carbon
atoms, or a combination of R.sup.1, a combination of R.sup.2, or a
combination of R.sup.1 and R.sup.2 may bond together to form an
aliphatic hydrocarbon ring with some carbon atoms in the oxygen
heterocycle to which they are attached, and in that event, each of
R.sup.1 and R.sup.2 is a straight, branched or cyclic alkylene
group of 1 to 10 carbon atoms, R.sup.3 is each independently a
straight, branched or cyclic monovalent hydrocarbon group of 1 to
10 carbon atoms, or a combination of R.sup.3 may bond together to
form an aliphatic hydrocarbon ring with some carbon atoms in the
ring to which they are attached, and in that event, each of R.sup.3
is a straight, branched or cyclic alkylene group of 1 to 10 carbon
atoms, and n is an integer of 0 to 6.
[0011] The preferred ester compounds have the following general
formulae (5) to (8):
##STR00003##
wherein A.sup.1, R.sup.1, R.sup.2, R.sup.3 and n are as defined
above, and R.sup.4 is hydrogen, fluorine, methyl or
trifluoromethyl.
[0012] Also the preferred ester compounds have the following
general formulae (9) to (12):
##STR00004##
wherein A.sup.2, R.sup.1, R.sup.2, R.sup.3, R.sup.4, and n are as
defined above, and k is 0 or 1.
[0013] In a second aspect, the invention provides a method for
preparing a polymerizable ester compound having the general formula
(1) or (2), comprising the steps of reacting an imine compound
having the general formula (21) with a compound having the general
formula (22) or (23) to form a hydroxyl-containing imine compound
having the general formula (24) or (25); subjecting the
hydroxyl-containing imine compound to acid hydrolysis to form a
hemiacetal compound having the general formula (17) or (18); and
acylating the hemiacetal compound to form a polymerizable ester
compound having the general formula (1) or (2).
##STR00005## ##STR00006##
Herein A.sup.1 is a polymerizable functional group having a
carbon-carbon double bond, R.sup.1 is each independently a
straight, branched or cyclic monovalent hydrocarbon group of 1 to
10 carbon atoms, R.sup.2 is each independently a hydrogen atom or a
straight, branched or cyclic monovalent hydrocarbon group of 1 to
10 carbon atoms, or a combination of R.sup.1, a combination of
R.sup.2, or a combination of R.sup.1 and R.sup.2 may bond together
to form an aliphatic hydrocarbon ring with some carbon atoms in the
oxygen heterocycle to which they are attached, and in that event,
each of R.sup.1 and R.sup.2 is a straight, branched or cyclic
alkylene group of 1 to 10 carbon atoms, and R.sup.5 is each
independently a straight, branched or cyclic monovalent hydrocarbon
group of 1 to 10 carbon atoms, or a combination of R.sup.5 may bond
together to form an aliphatic hydrocarbon ring with the carbon atom
to which they are attached.
[0014] In a third aspect, the invention provides a polymer
comprising at least recurring units derived from the polymerizable
ester compound defined above and having a weight average molecular
weight of 2,000 to 100,000.
[0015] In a preferred embodiment, the polymer further comprises
recurring units of at least one type selected from the following
general formula (R.sup.1).
##STR00007##
Herein R.sup.001 is hydrogen, fluorine, methyl, trifluoromethyl or
CH.sub.2CO.sub.2R.sup.003. R.sup.002 is hydrogen, methyl or
CO.sub.2R.sup.003. R.sup.003 is a straight, branched or cyclic
C.sub.1-C.sub.15 alkyl group. R.sup.004 is hydrogen or a monovalent
hydrocarbon group of 1 to 15 carbon atoms having at least one group
selected from among fluorinated substituent groups, carboxyl,
hydroxyl and cyano groups. At least one of R.sup.005 to R.sup.008
is a carboxyl group or a monovalent hydrocarbon group of 1 to 15
carbon atoms having at least one group selected from among
fluorinated substituent groups, carboxyl, hydroxyl and cyano groups
while the remaining of R.sup.005 to R.sup.008 are each
independently hydrogen or straight, branched or cyclic
C.sub.1-C.sub.15 alkyl groups, or two of R.sup.005 to R.sup.008 may
bond together to form an aliphatic hydrocarbon ring with the carbon
atom(s) to which they are attached, and in that event, at least one
of R.sup.005 to R.sup.008 is a divalent hydrocarbon group of 1 to
15 carbon atoms having at least one group selected from fluorinated
substituent groups, carboxyl, hydroxyl and cyano groups while the
remaining of R.sup.005 to R.sup.008 are each independently single
bonds, hydrogen atoms or straight, branched or cyclic
C.sub.1-C.sub.15 alkyl groups. R.sup.009 is a monovalent
hydrocarbon group of 3 to 15 carbon atoms containing a --CO.sub.2--
partial structure. At least one of R.sup.010 to R.sup.013 is a
monovalent hydrocarbon group of 2 to 15 carbon atoms containing a
--CO.sub.2-- partial structure while the remaining of R.sup.010 to
R.sup.013 are each independently hydrogen atoms or straight,
branched or cyclic C.sub.1-C.sub.15 alkyl groups, or two of
R.sup.010 to R.sup.013 may bond together to form an aliphatic
hydrocarbon ring with the carbon atom(s) to which they are
attached, and in that event, at least one of R.sup.010 to R.sup.013
is a divalent hydrocarbon group of 1 to 15 carbon atoms having a
--CO.sub.2-- partial structure while the remaining of R.sup.010 to
R.sup.013 are each independently single bonds, hydrogen atoms or
straight, branched or cyclic C.sub.1-C.sub.15 alkyl groups.
R.sup.014 is a polycyclic hydrocarbon group having 7 to 15 carbon
atoms or an alkyl group containing such a polycyclic hydrocarbon
group. R.sup.015 is an acid labile group, X is CH.sub.2 or an
oxygen atom; and k is 0 or 1.
[0016] In the preferred polymer, the recurring units derived from
the polymerizable ester compound of any one of formulae (1) to (4)
are present in a molar fraction of at least 5%.
[0017] In a fourth aspect, the invention provides a resist
composition comprising the polymer defined above; specifically, a
resist composition comprising (A) the polymer, (B) an acid
generator, and (C) an organic solvent; and more specifically a
resist composition comprising (A) the polymer, (B) an acid
generator, (C) an organic solvent, and (D) a sensitivity
regulator.
[0018] In a fifth aspect, the invention provides a process for
forming a pattern, comprising the steps of applying the resist
composition defined above onto a substrate to form a resist
coating; heat treating the coating and exposing to high-energy
radiation or electron beam through a photomask; and optionally heat
treating the exposed coating and developing with a developer.
[0019] It is noted that immersion lithography can be applied to the
resist composition of the invention. The immersion lithography
involves prebaking a resist film and exposing the resist film to
light through a projection lens with a medium interposed between
the resist film and the projection lens. The ArF immersion
lithography uses deionized water as the immersion medium. This
technology, combined with a projection lens having a numerical
aperture of at least 1.0, is important for the ArF lithography to
survive to the 65 nm node, with a further development thereof being
accelerated.
[0020] The resist composition of the invention allows the feature
size of the pattern after development to be reduced by various
shrinkage techniques. For example, the hole size can be shrunk by
such known techniques as thermal flow, RELACS, SAFIRE, and WASOOM.
More effective shrinkage of hole size by thermal flow is possible
particularly when the inventive polymer is blended with a
hydrogenated cycloolefin ring-opening metathesis polymer (ROMP)
having a low Tg.
BENEFITS OF THE INVENTION
[0021] A resist composition comprising a polymer resulting from the
polymerizable ester compound of the invention as a base resin is
thermally stable and sensitive to high-energy radiation, has
excellent sensitivity and resolution, and lends itself to
micropatterning with electron beam or deep-UV. Especially because
of the minimized absorption at the exposure wavelength of an ArF or
KrF excimer laser, a fine-feature pattern having sidewalls
perpendicular to the substrate can easily be formed. Since no
low-molecular-weight fractions are generated after deprotection,
advantageously the level of outgassing is minimized.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] The singular forms "a," "an" and "the" include plural
referents unless the context clearly dictates otherwise.
[0023] The notation (Cn-Cm) means a group containing from n to m
carbon atoms per group.
Ester Compound
[0024] The ester compounds of the invention have the following
general formulae (1) to (4):
##STR00008##
Herein A.sup.1 is a polymerizable functional group having a
carbon-carbon double bond, such as vinyl, allyl, 1-propenyl,
isopropenyl, norbornenyl, and
tetracyclo[4.4.0.1.sup.2,5.1.sup.7,10]dodecenyl. A.sup.2 is an
oxygen atom, methylene group or ethylene group. R.sup.1 is each
independently a straight, branched or cyclic monovalent hydrocarbon
group of 1 to 10 carbon atoms, examples of which include methyl,
ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl,
tert-amyl, n-pentyl, n-hexyl, cyclopentyl, cyclohexyl,
bicyclo[2.2.1]heptyl, bicyclo[2.2.2]octyl, bicyclo[3.3.1]nonyl,
bicyclo[4.4.0]decanyl, and adamantyl. R.sup.2 is each independently
a hydrogen atom or a straight, branched or cyclic monovalent
hydrocarbon group of 1 to 10 carbon atoms, examples of which
include hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl,
sec-butyl, tert-butyl, tert-amyl, n-pentyl, n-hexyl, cyclopentyl,
cyclohexyl, bicyclo[2.2.1]heptyl, bicyclo[2.2.2]octyl,
bicyclo[3.3.1]nonyl, bicyclo[4.4.0]decanyl, and adamantyl.
Alternatively, a combination of R.sup.1, a combination of R.sup.2,
or a combination of R.sup.1 and R.sup.2 may bond together to form
an aliphatic hydrocarbon ring with some carbon atoms in the oxygen
heterocycle to which they are attached, and in that event, each of
R.sup.1 and R.sup.2 is a straight, branched or cyclic
C.sub.1-C.sub.10 alkylene group. Examples of the hydrocarbon ring
include cyclopropane, cyclobutane, cyclopentane, cyclohexane,
bicyclo[2.2.1]heptane, bicyclo[2.2.2]octane, bicyclo[3.3.1]nonane,
bicyclo[4.4.0]decane, and adamantane. R.sup.3 is each independently
a straight, branched or cyclic monovalent hydrocarbon group of 1 to
10 carbon atoms, examples of which include methyl, ethyl, n-propyl,
isopropyl, n-butyl, sec-butyl, tert-butyl, tert-amyl, n-pentyl,
n-hexyl, cyclopentyl, cyclohexyl, bicyclo[2.2.1]heptyl,
bicyclo[2.2.2]octyl, bicyclo[3.3.1]nonyl, bicyclo[4.4.0]decanyl,
and adamantyl. Alternatively, a combination of R.sup.3 may bond
together to form an aliphatic hydrocarbon ring with some carbon
atoms in the ring to which they are attached, and in that event,
each of R.sup.3 is a straight, branched or cyclic C.sub.1-C.sub.10
alkylene group. Examples of the hydrocarbon ring include
cyclopropane, cyclobutane, cyclopentane, cyclohexane,
bicyclo[2.2.1]heptane, bicyclo[2.2.2]octane, bicyclo[3.3.1]nonane,
bicyclo[4.4.0]decane, and adamantane. The subscript n is an integer
of 0 to 6.
[0025] The ester compound of the invention is characterized in that
deprotection occurs without beta-elimination. Provided that for
formulae (1) to (4) and similar formulae, the acetal carbon atom
sandwiched between two oxygen atoms is designated .alpha.-carbon, a
carbon atom at a vicinal position to .alpha.-carbon is designated
.beta.-carbon, and a hydrogen atom on .beta.-carbon is designated
.beta.-hydrogen, the term ".beta.-elimination" as used herein means
that deprotection occurs as a result of .beta.-hydrogen being
eliminated. For example, the following scheme illustrates the
deprotection reaction of 2-tetrahydropyranyl ester by
.beta.-elimination mechanism.
##STR00009##
By contrast, in formulae (1) and (2), no hydrogen atoms are present
on .beta.-carbon. In formulae (3) and (4), hydrogen atoms may be
present on .beta.-carbon, but .beta.-elimination cannot occur due
to steric hindrance.
[0026] The deprotection mechanism other than the .beta.-elimination
that is deemed for the compounds of the invention and cyclic
hemiacetal esters such as 2-tetrahydropyranyl esters to undergo is
deprotection by hydrolysis or nucleophilic attack. For example, if
a minute amount of water is present in the resist system, the
compound of formula (I) undergoes acid hydrolysis into a carboxylic
acid and a hemiacetal compound according to the scheme shown
below.
##STR00010##
[0027] For the ester compounds of formulae (1) to (4), the probable
deprotection mechanism is only deprotection by acid hydrolysis or
nucleophilic attack. For 2-tetrahydropyranyl, 1-ethoxyethyl and
analogous esters, not only deprotection by acid hydrolysis or
nucleophilic attack, but also deprotection by the
.beta.-elimination mechanism can occur. Thus, the ester compounds
of formulae (1) to (4) can be suppressed in reactivity for
deprotection, as compared with the 2-tetrahydropyranyl,
1-ethoxyethyl and analogous esters.
[0028] The ester compounds of the invention are characterized by a
cyclic hemiacetal ester structure, so that no low-molecular-weight
fractions may be generated after deprotection. Therefore, when the
ester compounds of the invention are used as a resist resin, an
advantage of minimized outgassing is available.
[0029] Of the ester compounds having formulae (1) to (4), those
having the following general formulae (5) to (8) are preferred.
##STR00011##
Herein A.sup.1, R.sup.1, R.sup.2, R.sup.3 and n are as defined
above, and R.sup.4 is a hydrogen atom, fluorine atom, methyl group
or trifluoromethyl group.
[0030] Of the ester compounds having formulae (1) to (4), those
having the following general formulae (9) to (12) are also
preferred.
##STR00012##
Herein A.sup.2, R.sup.1, R.sup.2, R.sup.3, R.sup.4 and n are as
defined above, and k is 0 or 1.
[0031] Illustrative non-limiting examples of the ester compounds
having formulae (1) to (12) are given below.
##STR00013## ##STR00014## ##STR00015## ##STR00016## ##STR00017##
##STR00018## ##STR00019## ##STR00020## ##STR00021## ##STR00022##
##STR00023## ##STR00024## ##STR00025## ##STR00026##
##STR00027##
Herein R.sup.4 is as defined above.
[0032] According to the invention, the ester compounds having
formulae (1) and (2) may be synthesized, for example, as seen from
the reaction scheme shown below, through the first step of
synthesizing intermediate hemiacetal compounds having formulae (17)
and (18) by procedure i) or ii), and the second step of acylating
the hydroxyl group on the intermediate hemiacetal compounds by
procedure iii) or iv). Also, the ester compounds having formulae
(3) and (4) may be synthesized, for example, as seen from the
reaction scheme shown below, through the first step of synthesizing
intermediate hemiacetal compounds having formulae (19) and (20) by
procedure i), and the second step of acylating the intermediate
hemiacetal compounds by procedure iii) or iv). The method of
preparing the ester compounds having formulae (1) to (4) is not
limited to these.
##STR00028## ##STR00029## ##STR00030## ##STR00031##
Herein A.sup.1, A.sup.2, R.sup.1 to R.sup.3, and n are as defined
above, and R.sup.5 is each independently a straight, branched or
cyclic monovalent hydrocarbon group of 1 to 10 carbon atoms, or a
combination of R.sup.5 may bond together to form an aliphatic
hydrocarbon ring with the carbon atom to which they are attached,
and in that event, each of R.sup.5 is a straight, branched or
cyclic alkylene group of 1 to 10 carbon atoms, and Ac is an acetyl
group.
[0033] Examples of suitable reducing agents which can be used
herein include hydrogen, boran, alkyl borans, dialkyl borans,
bis(3-methyl-2-butyl)boran, dialkylsilanes, trialkylsilanes,
alkylaluminum, dialkylaluminum; metal hydrides such as sodium
hydride, lithium hydride, potassium hydride and calcium hydride;
and complex hydrides such as sodium borohydride, lithium
borohydride, potassium borohydride, calcium borohydride, sodium
aluminum hydride, lithium aluminum hydride, sodium
trimethoxyborohydride, lithium trimethoxyaluminohydride, lithium
diethoxyaluminohydride, lithium tri-tert-butoxyaluminohydride,
sodium bis(2-methoxyethoxy)aluminohydride, lithium
triethylborohydride, and diisobutylaluminum hydride, and alkoxy- or
alkyl derivatives thereof. In the relevant reaction, use of
diisobutylaluminum hydride or bis(3-methyl-2-butyl)boran is
especially preferred.
[0034] Examples of suitable acids which can be used herein include
mineral acids such as hydrochloric acid, hydrobromic acid, sulfuric
acid, and nitric acid, and organic acids such as acetic acid,
trifluoroacetic acid, oxalic acid, methanesulfonic acid,
benzenesulfonic acid, and p-toluenesulfonic acid. The acids may be
used alone or in admixture. In the relevant reaction, use of acetic
acid is especially preferred.
[0035] Examples of suitable bases which can be used herein include
alkoxides such as sodium methoxide, sodium ethoxide, lithium
methoxide, lithium ethoxide, lithium tert-butoxide, and potassium
tert-butoxide; organic amines such as pyridine, triethylamine,
N,N-dimethylaniline, and 4-dimethylaminopyridine; inorganic
hydroxides such as sodium hydroxide, lithium hydroxide, potassium
hydroxide, barium hydroxide, and tetra-n-butylammonium hydroxide;
inorganic carbonates such as sodium carbonate, sodium hydrogen
carbonate, lithium carbonate, and potassium carbonate; alkyl metal
compounds such as trityllithium, tritylsodium, tritylpotassium,
methyllithium, phenyllithium, n-butyllithium, sec-butyllithium,
tert-butyllithium, and ethylmagnesium bromide; and metal amides
such as sodium amide, potassium amide, lithium diisopropylamide,
potassium diisopropylamide, lithium dicyclohexylamide, potassium
dicyclohexylamide, lithium 2,2,6,6-tetramethylpiperidine, lithium
bistrimethylsilylamide, sodium bistrimethylsilylamide, potassium
bistrimethylsilylamide, lithium isopropylcyclohexylamide, and
magnesium bromide diisopropylamide. In the relevant reaction, use
of ethylmagnesium bromide or lithium diisopropylamide is especially
preferred.
[0036] With regard to the first step included in the preparation
method of ester compounds, procedure i) for the synthesis of
intermediate hemiacetal compounds having formulae (17) to (20) and
procedure ii) for the synthesis of intermediate hemiacetal
compounds having formulae (17) and (18) are described below.
[0037] i) One procedure is to synthesize an intermediate hemiacetal
compound (17) by reducing a lactone compound (13).
[0038] The amount of the reducing agent used varies with the
identity of reducing agent used and reaction conditions and is
generally 0.5 to 2.0 moles, especially 0.9 to 1.2 moles, per mole
of lactone compound (13). Suitable solvents include hydrocarbons
such as hexane, heptane, benzene, toluene, xylene, and cumene; and
ethers such as dibutyl ether, diethylene glycol diethyl ether,
diethylene glycol dimethyl ether, tetrahydrofuran, and 1,4-dioxane,
which may be used alone or in admixture. The reaction temperature
and time vary widely with other conditions. When diisobutylaluminum
hydride is used as the reducing agent, for example, the reaction
temperature is in a range from -79.degree. C. to 25.degree. C., and
preferably from -70.degree. C. to 0.degree. C. The reaction time is
determined as appropriate by monitoring the reaction process by gas
chromatography (GC) or silica gel thin-layer chromatography (TLC)
because it is desirable from the yield aspect to drive the reaction
to completion. Usually the reaction time is about 0.5 to about 10
hours. Thereafter, water is added to the reaction mixture to quench
the reaction. The organic layer is separated, dried, and
concentrated, yielding intermediate hemiacetal compound (17). If
necessary, the compound may be purified by standard techniques like
distillation and chromatography. Likewise, intermediate hemiacetal
compounds (18), (19) and (20) can be synthesized from lactone
compounds (14), (15) and (16), respectively.
[0039] ii) In an alternative procedure, an imine compound (21) is
converted into an N-metal enamine compound by withdrawing
.alpha.-hydrogen therefrom with the aid of a base. The N-metal
enamine compound is reacted with an oxirane compound (22) to form a
hydroxyl-containing imine compound (24). Then the imine compound
(24) is treated with an acid so that conversion from imine to
aldehyde and cyclization reaction occur in sequence whereby the
intermediate hemiacetal compound (17) is synthesized.
[0040] The amount of the base used varies with reaction conditions.
When ethylmagnesium bromide is used as the base, for example, an
appropriate amount is 0.8 to 3.0 moles, and especially 1.1 to 1.5
moles, per mole of imine compound (21). Suitable solvents include
hydrocarbons such as hexane, heptane, benzene, toluene, xylene, and
cumene; and ethers such as dibutyl ether, diethylene glycol diethyl
ether, diethylene glycol dimethyl ether, tetrahydrofuran, and
1,4-dioxane, which may be used alone or in admixture. The reaction
temperature is in a range from -20.degree. C. to 80.degree. C., and
preferably from 0.degree. C. to 50.degree. C. The reaction time is
preferably about 5 minutes to about 30 hours, more preferably about
10 minutes to about 5 hours. After the reaction with the base,
oxirane compound (22) is added, desirably in an amount of 0.8 to
5.0 moles, more desirably 1.1 to 3.0 moles per mole of imine
compound (21). The reaction temperature is in a range from
-20.degree. C. to 60.degree. C., and preferably from 0.degree. C.
to 30.degree. C. The reaction time is determined as appropriate by
monitoring the reaction process by GC or silica gel TLC because it
is desirable from the yield aspect to drive the reaction to
completion. Usually the reaction time is about 0.5 to about 10
hours. From the reaction mixture, hydroxyl-containing imine
compound (24) may be collected by ordinary aqueous workup.
Thereafter, an acid is added to hydroxyl-containing imine compound
(24). From the reaction mixture, hemiacetal compound (17) is
collected by ordinary aqueous workup. The amount of the acid used
is 0.5 to 3.0 moles, and preferably 0.8 to 1.5 moles, per mole of
imine compound (21). The reaction time is determined as appropriate
by monitoring the reaction process by GC or silica gel TLC because
it is desirable from the yield aspect to drive the reaction to
completion. Usually the reaction time is about 1 to about 30 hours.
If necessary, the intermediate hemiacetal compound may be purified
by standard techniques like distillation and chromatography.
Likewise, intermediate hemiacetal compound (18) can be synthesized
using oxetane compound (23) instead of oxirane compound (22).
[0041] With regard to the second step included in the preparation
method of ester compounds, procedures iii) and iv) for the
synthesis of ester compounds (1) to (4) are described below.
[0042] iii) The second step is the acylation of intermediate
hemiacetal compound (17). For the acylation reaction, well-known
ester forming methods including reaction with an acylating agent,
reaction with a carboxylic acid, and transesterification reaction
may be applicable.
[0043] In the case of reaction with an acylating agent, preferably
the alcohol compound, an acylating agent, and a base are
sequentially or simultaneously added to a solvent for reaction. The
solvent used herein is selected from among chlorinated solvents
such as methylene chloride, chloroform, and trichloroethylene;
hydrocarbons such as hexane, heptane, benzene, toluene, xylene and
cumene; ethers such as dibutyl ether, diethylene glycol diethyl
ether, diethylene glycol dimethyl ether, tetrahydrofuran, and
1,4-dioxane; nitriles such as acetonitrile; ketones such as acetone
and 2-butanone; esters such as ethyl acetate and n-butyl acetate;
and aprotic polar solvents such as N,N-dimethylformamide, dimethyl
sulfoxide and hexamethylphosphoric triamide, and mixtures thereof.
The acylating agent is selected from among acid halides such as
acrylic acid chloride, methacrylic acid chloride, acrylic acid
bromide, methacrylic acid bromide, and
.alpha.-trifluoromethylacrylic acid chloride; and acid anhydrides
such as acrylic anhydride, methacrylic anhydride,
.alpha.-trifluoromethylacrylic anhydride, acrylic/trifluoroacetic
mixed acid anhydride, methacrylic/trifluoroacetic mixed acid
anhydride, .alpha.-trifluoromethylacrylic/trifluoroacetic mixed
acid anhydride, acrylic/p-nitrobenzoic mixed acid anhydride,
methacrylic/p-nitrobenzoic mixed acid anhydride, ethyl
acrylate/carbonic mixed acid anhydride, and ethyl
methacrylate/carbonic mixed acid anhydride. The base is selected
from among triethylamine, diisopropylethylamine,
N,N-dimethylaniline, pyridine, and 4-dimethylaminopyridine. The
reaction temperature may be selected as appropriate in accordance
with the identity of acylating agent and other reaction conditions
and is preferably in the range from -50.degree. C. to approximately
the boiling point of the solvent, and more preferably in the range
from -20.degree. C. to approximately room temperature. The amount
of acylating agent used depends on the structure of alcohol
compound used and is generally 1 to 40 moles, and preferably 1 to 5
moles per mole of the alcohol compound.
[0044] The reaction with a carboxylic acid is a dehydration
reaction between the alcohol compound and a corresponding
carboxylic acid such as acrylic acid, methacrylic acid or
.alpha.-trifluoromethylacrylic acid, typically in the presence of
an acid catalyst. The amount of the carboxylic acid used depends on
the structure and is usually 1 to 40 moles, preferably 1 to 5 moles
per mole of the alcohol compound. Examples of the acid catalyst
include mineral acids such as hydrochloric acid, hydrobromic acid,
sulfuric acid and nitric acid, and organic acids such as oxalic
acid, trifluoroacetic acid, methanesulfonic acid, benzenesulfonic
acid and p-toluenesulfonic acid, and mixtures thereof. The amount
of the acid catalyst used is a catalytic amount in the range of
0.001 to 1 mole, preferably 0.01 to 0.05 mole per mole of the
alcohol compound. The solvent used herein is as exemplified above
for the reaction with acylating agent. The reaction temperature is
preferably in a range from -50.degree. C. to approximately the
boiling point of the solvent. It is also preferable to carry out
the reaction in a solvent comprising a hydrocarbon such as hexane,
heptane, benzene, toluene, xylene or cumene, while azeotroping off
the water of reaction. In this case, the water may be distilled off
by refluxing under atmospheric pressure at the boiling point of the
solvent, or under reduced pressure at a temperature below the
boiling point.
[0045] In the case of transesterification reaction, the alcohol
compound is reacted with a corresponding carboxylic acid ester,
such as acrylate, methacrylate or .alpha.-trifluoromethylacrylate
in the presence of a catalyst, and the resulting alcohol is
removed. The carboxylic acid ester used herein is preferably
selected from primary alkyl esters, with methyl, ethyl and n-propyl
esters being preferred from the standpoints of cost and ease of
reaction. The amount of carboxylic acid ester used depends on the
structure and is in a range of 1 to 40 moles, and preferably 1 to 5
moles per mole of the alcohol compound. Examples of the catalyst
used include mineral acids such as hydrochloric acid, hydrobromic
acid, sulfuric acid and nitric acid; organic acids such as oxalic
acid, trifluoroacetic acid, methanesulfonic acid, benzenesulfonic
acid and p-toluenesulfonic acid; bases such as sodium methoxide,
sodium ethoxide, potassium t-butoxide, and 4-dimethylaminopyridine;
salts such as sodium cyanate, potassium cyanate, sodium acetate,
potassium acetate, calcium acetate, tin acetate, aluminum acetate,
aluminum acetoacetate, and alumina; Lewis acids such as aluminum
trichloride, aluminum ethoxide, aluminum isopropoxide, boron
trifluoride, boron trichloride, boron tribromide, tin
tetrachloride, tin tetrabromide, dibutyltin dichloride, dibutyltin
dimethoxide, titanium(IV) ethoxide, titanium(IV) isopropoxide, and
titanium oxide, which may be used alone or in admixture. The amount
of catalyst used is in a range of 0.001 to 20 moles, and preferably
0.01 to 0.05 mole per mole of the alcohol compound. The reaction
may be performed in a solventless system (the reactant carboxylic
acid ester itself may be used as a solvent), which is preferable
because of no need for extra operations like concentration and
solvent recovery. A solvent may be used in an auxiliary manner for
the purpose of preventing the end product and reactants from
polymerization. Examples of the solvent, if used, include
hydrocarbons such as hexane, heptane, benzene, toluene, xylene, and
cumene; and ethers such as dibutyl ether, diethylene glycol diethyl
ether, diethylene glycol dimethyl ether, tetrahydrofuran, and
1,4-dioxane, which may be used alone or in admixture. The reaction
temperature may be selected as appropriate depending on the
identity of carboxylic acid ester and other reaction conditions.
Most often, the reaction is carried out while heating, typically at
a temperature near the boiling point of the low-boiling alcohol
formed by transesterification such as methanol, ethanol or
1-propanol. Better results are obtained by carrying out the
reaction while distilling off the alcohol formed. The alcohol may
be distilled off under reduced pressure and at a temperature lower
than its boiling point.
[0046] If necessary, the resulting ester compound (1) may be
purified by standard techniques such as chromatography,
distillation and recrystallization. Using the known ester
preparation methods described above, ester compounds (2), (3) and
(4) can be synthesized from intermediate hemiacetal compounds (18),
(19) and (20), respectively.
[0047] iv) In an alternative procedure of the second step, ester
compound (1) can be synthesized by once acetylating the
intermediate hemiacetal compound and then effecting acetal exchange
reaction with a carboxylic acid. Acetylation of intermediate
hemiacetal compound (17) may be performed by a standard technique
using pyridine and acetic anhydride. If necessary, the resulting
acetate (26) may be purified by standard techniques such as
chromatography, distillation and recrystallization.
[0048] Subsequently, carboxylic acid (30), for example, acrylic
acid, methacrylic acid or .alpha.-trifluoromethylacrylic acid is
added to acetate (26) and optionally, an acid catalyst added. The
amount of carboxylic acid used is desirably 1.0 to 20.0 moles, and
more desirably 2.0 to 10.0 moles per mole of acetate (26). Examples
of suitable acid catalysts which can be used herein include mineral
acids such as hydrochloric acid, hydrobromic acid, sulfuric acid,
and nitric acid, organic acids such as oxalic acid, trifluoroacetic
acid, methanesulfonic acid, benzenesulfonic acid, and
p-toluenesulfonic acid, organic salts such as pyridinium
p-toluenesulfonate, and acidic ion-exchange resins. The amount of
acid catalyst used is desirably 0 to 0.20 mole, and more desirably
0 to 0.10 moles per mole of acetate (26). Although the reaction
generates an equilibrium mixture of acetate (26) and ester compound
(1), the equilibrium can be biased toward the end product, ester
compound (1) by distilling off the acetic acid formed under reduced
pressure. From the reaction mixture, ester compound (1) may be
collected by ordinary aqueous workup. If necessary, ester compound
(1) may be purified by standard techniques such as chromatography,
distillation and recrystallization. In some cases, the reaction
mixture may be directly purified without the aqueous workup.
Likewise, ester compounds (2), (3) and (4) can be synthesized from
intermediate hemiacetal compounds (18), (19) and (20),
respectively.
Polymer
[0049] The polymers of the invention are characterized by
comprising recurring units derived from ester compounds having
formulae (1) to (4).
[0050] The recurring units derived from ester compounds having
formulae (1) to (4) include those having the following formulae
(1a) to (4c). It is noted that units of formulae (1c), (2c), (3c),
and (4c) are obtained by carrying out ring-opening metathesis
polymerization (ROMP) and hydrogenation on a double bond.
##STR00032## ##STR00033## ##STR00034##
Herein, A.sup.2, R.sup.1 to R.sup.4, and n are as defined above,
and k.sup.1 is 0 or 1.
[0051] In addition to the recurring units of formulae (1a) to (4c),
the polymer may further comprise recurring units derived from
another monomer having a polymerizable double bond.
[0052] The recurring units derived from the monomer having a
polymerizable double bond include, but are not limited to, those
having the following general formula (R.sup.1).
##STR00035##
Herein R.sup.001 is a hydrogen atom, fluorine atom, methyl group,
trifluoromethyl group or CH.sub.2CO.sub.2R.sup.003.
[0053] R.sup.002 is a hydrogen atom, methyl group or
CO.sub.2R.sup.003.
[0054] R.sup.003 is a straight, branched or cyclic C.sub.1-C.sub.15
alkyl group, examples of which include methyl, ethyl, propyl,
isopropyl, n-butyl, sec-butyl, tert-butyl, tert-amyl, n-pentyl,
n-hexyl, cyclopentyl, cyclohexyl, ethylcyclopentyl,
butylcyclopentyl, ethylcyclohexyl, butylcyclohexyl, adamantyl,
ethyladamantyl, and butyladamantyl.
[0055] R.sup.004 is a hydrogen atom or a monovalent hydrocarbon
group of 1 to 15 carbon atoms having at least one group selected
from among fluorinated substituent groups, carboxyl, hydroxyl and
cyano groups. Examples include hydrogen, carboxyethyl,
carboxybutyl, carboxycyclopentyl, carboxycyclohexyl,
carboxynorbornyl, carboxyadamantyl, hydroxyethyl, hydroxybutyl,
hydroxycyclopentyl, hydroxycyclohexyl, hydroxynorbornyl,
hydroxyadamantyl,
[2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl]-cyclohexyl,
and
bis[2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl]-cyclohexyl.
[0056] At least one of R.sup.005 to R.sup.008 is a carboxyl group
or a monovalent hydrocarbon group of 1 to 15 carbon atoms having at
least one group selected from among fluorinated substituent groups,
carboxyl, hydroxyl and cyano groups while the remaining of
R.sup.005 to R.sup.008 are each independently hydrogen or straight,
branched or cyclic C.sub.1-C.sub.15 alkyl groups. Examples of
suitable monovalent C.sub.1-C.sub.15 hydrocarbon groups having at
least one group selected from among fluorinated substituent groups,
carboxyl groups, hydroxyl groups and cyano groups include
carboxymethyl, carboxyethyl, carboxybutyl, hydroxymethyl,
hydroxyethyl, hydroxybutyl, 2-carboxyethoxycarbonyl,
4-carboxybutoxycarbonyl, 2-hydroxyethoxycarbonyl,
4-hydroxybutoxycarbonyl, carboxycyclopentyloxycarbonyl,
carboxycyclohexyloxycarbonyl, carboxynorbornyloxycarbonyl,
carboxyadamantyloxycarbonyl, hydroxycyclopentyloxycarbonyl,
hydroxycyclohexyloxycarbonyl, hydroxynorbornyloxycarbonyl,
hydroxyadamantyloxycarbonyl,
[2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl]-cyclohexyloxycarbony-
l, and
bis[2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl]-cyclohexylo-
xycarbonyl. Suitable straight, branched or cyclic C.sub.1-C.sub.15
alkyl groups are as exemplified for R.sup.003.
[0057] Two of R.sup.005 to R.sup.008 (for example, a pair of
R.sup.005 and R.sup.006, R.sup.006 and R.sup.007, or R.sup.007 and
R.sup.008) may bond together to form an aliphatic hydrocarbon ring
with the carbon atom(s) to which they are attached, and in that
event, at least one of R.sup.005 to R.sup.008 is a divalent
hydrocarbon group of 1 to 15 carbon atoms having at least one group
selected from fluorinated substituent groups, carboxyl, hydroxyl
and cyano groups while the remaining of R.sup.005 to R.sup.008 are
each independently single bonds, hydrogen atoms or straight,
branched or cyclic C.sub.1-C.sub.15 alkyl groups. Suitable divalent
C.sub.1-C.sub.15 hydrocarbon groups having at least one group
selected from fluorinated substituent groups, carboxyl, hydroxyl
and cyano groups include those exemplified above as the monovalent
hydrocarbon groups having at least one group selected from
fluorinated substituent groups, carboxyl, hydroxyl and cyano
groups, with one hydrogen atom eliminated therefrom.
[0058] R.sup.009 is a monovalent hydrocarbon group of 3 to 15
carbon atoms containing a --CO.sub.2-- partial structure. Examples
include 2-oxooxolan-3-yl, 4,4-dimethyl-2-oxooxolan-3-yl,
4-methyl-2-oxooxan-4-yl, 2-oxo-1,3-dioxolan-4-ylmethyl, and
5-methyl-2-oxooxolan-5-yl.
[0059] At least one of R.sup.010 to R.sup.013 is a monovalent
hydrocarbon group of 2 to 15 carbon atoms containing a --CO.sub.2--
partial structure while the remaining of R.sup.010 to R.sup.013 are
each independently hydrogen atoms or straight, branched or cyclic
C.sub.1-C.sub.15 alkyl groups. Illustrative examples of suitable
monovalent C.sub.2-C.sub.15 hydrocarbon groups containing a
--CO.sub.2-partial structure include 2-oxooxolan-3-yloxycarbonyl,
4,4-dimethyl-2-oxooxolan-3-yloxycarbonyl,
4-methyl-2-oxooxan-4-yloxycarbonyl,
2-oxo-1,3-dioxolan-4-ylmethyloxycarbonyl, and
5-methyl-2-oxooxolan-5-yloxycarbonyl. Suitable straight, branched
or cyclic C.sub.1-C.sub.15 alkyl groups are as exemplified for
R.sup.003.
[0060] Two of R.sup.010 to R.sup.013 (for example, a pair of
R.sup.010 and R.sup.011, R.sup.011 and R.sup.12, or R.sup.012 and
R.sup.013) may bond together to form an aliphatic hydrocarbon ring
with the carbon atom(s) to which they are attached, and in that
event, at least one of R.sup.010 to R.sup.013 is a divalent
hydrocarbon group of 1 to 15 carbon atoms having a --CO.sub.2--
partial structure while the remaining of R.sup.010 to R.sup.013 are
each independently single bonds, hydrogen atoms or straight,
branched or cyclic C.sub.1-C.sub.15 alkyl groups. Illustrative
examples of suitable divalent C.sub.1-C.sub.15 hydrocarbon groups
containing a --CO.sub.2-- partial structure include
1-oxo-2-oxapropane-1,3-diyl, 1,3-dioxo-2-oxapropane-1,3-diyl,
1-oxo-2-oxabutane-1,4-diyl, and 1,3-dioxo-2-oxabutane-1,4-diyl, as
well as those exemplified as the monovalent hydrocarbon groups
containing a --CO.sub.2-partial structure, with one hydrogen atom
eliminated therefrom.
[0061] R.sup.014 is a polycyclic hydrocarbon group having 7 to 15
carbon atoms or an alkyl group containing such a polycyclic
hydrocarbon group. Examples include norbornyl, bicyclo[3.3.1]nonyl,
tricyclo[5.2.1.0.sup.2,6]decyl, adamantyl, norbornylmethyl,
adamantylmethyl, and alkyl- or cycloalkyl-substituted derivatives
thereof.
[0062] R.sup.015 is an acid labile group, which will be described
later in detail.
[0063] X is CH.sub.2 or an oxygen atom, and k is 0 or 1.
[0064] The acid labile group represented by R.sup.0.5 may be
selected from a variety of such groups. It is a group to be
deprotected by the acid generated from the photoacid generator to
be described later and may be any of well-known acid labile groups
which are commonly used in prior art resist materials, especially
chemically amplified resist materials. Examples of the acid labile
group are groups of the following general formulae (L1) to (L4),
tertiary alkyl groups of 4 to 20 carbon atoms, preferably 4 to 15
carbon atoms, trialkylsilyl groups in which each alkyl moiety has 1
to 6 carbon atoms, and oxoalkyl groups of 4 to 20 carbon atoms.
##STR00036##
[0065] Herein the broken line denotes a valence bond. R.sup.L01 and
R.sup.L02 are hydrogen or straight, branched or cyclic alkyl groups
of 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. Exemplary
alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl,
sec-butyl, tert-butyl, cyclopentyl, cyclohexyl, 2-ethylhexyl,
n-octyl, and adamantyl. R.sup.L03 is a monovalent hydrocarbon group
of 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, which may
contain a hetero atom such as oxygen, examples of which include
unsubstituted straight, branched or cyclic alkyl groups and
substituted forms of such alkyl groups in which some hydrogen atoms
are replaced by hydroxyl, alkoxy, oxo, amino, alkylamino or the
like. Illustrative examples of the straight, branched or cyclic
alkyl groups are as exemplified above for R.sup.L01 and R.sup.L02,
and examples of the substituted alkyl groups are as shown
below.
##STR00037##
[0066] A pair of R.sup.L01 and R.sup.L02, R.sup.L01 and R.sup.L03,
or R.sup.L02 and R.sup.L03 may together form an aliphatic ring with
carbon and oxygen atoms to which they are attached. The cyclization
group of R.sup.L01, R.sup.L02 and R.sup.L03 is a straight or
branched alkylene group of 1 to 18 carbon atoms, preferably 1 to 10
carbon atoms when they form a ring.
[0067] R.sup.L04 is a tertiary alkyl group of 4 to 20 carbon atoms,
preferably 4 to 15 carbon atoms, a trialkylsilyl group in which
each alkyl moiety has 1 to 6 carbon atoms, an oxoalkyl group of 4
to 20 carbon atoms, or a group of formula (L1). Exemplary tertiary
alkyl groups are tert-butyl, tert-amyl, 1,1-diethylpropyl,
2-cyclopentylpropan-2-yl, 2-cyclohexylpropan-2-yl,
2-(bicyclo[2.2.1]heptan-2-yl)propan-2-yl,
2-(adamantan-1-yl)propan-2-yl,
2-(tricyclo[5.2.1.0.sup.2,6]decan-8-yl)propan-2-yl,
2-(tetracyclo[4.4.0.1.sup.2,5.1.sup.7,10]dodecan-3-yl)propan-2-yl,
1-ethylcyclopentyl, 1-butylcyclopentyl, 1-ethylcyclohexyl,
1-butylcyclohexyl, 1-ethyl-2-cyclopentenyl, 1-ethyl-2-cyclohexenyl,
2-methyl-2-adamantyl, 2-ethyl-2-adamantyl,
8-methyl-8-tricyclo[5.2.1.0.sup.2,6]decyl,
8-ethyl-8-tricyclo[5.2.1.0.sup.2,6]decyl,
3-methyl-3-tetracyclo[4.4.0.1.sup.2,5.1.sup.7,10]dodecyl,
3-ethyl-3-tetracyclo[4.4.0.1.sup.2,5.1.sup.7,10]dodecyl, and the
like. Exemplary trialkylsilyl groups are trimethylsilyl,
triethylsilyl, and dimethyl-tert-butylsilyl. Exemplary oxoalkyl
groups are 3-oxocyclohexyl, 4-methyl-2-oxooxan-4-yl, and
5-methyl-2-oxooxolan-5-yl. Letter y is an integer of 0 to 6.
[0068] In formula (L3), R.sup.L05 is an optionally substituted,
straight, branched or cyclic C.sub.1-C.sub.10 alkyl group or an
optionally substituted C.sub.6-C.sub.20 aryl group. Examples of the
optionally substituted alkyl groups include straight, branched or
cyclic alkyl groups such as methyl, ethyl, propyl, isopropyl,
n-butyl, sec-butyl, tert-butyl, tert-amyl, n-pentyl, n-hexyl,
cyclopentyl, cyclohexyl, and bicyclo[2.2.1]heptyl, and substituted
forms of such groups in which some hydrogen atoms are replaced by
hydroxyl, alkoxy, carboxy, alkoxycarbonyl, oxo, amino, alkylamino,
cyano, mercapto, alkylthio, sulfo or other groups or in which some
methylene groups are replaced by oxygen or sulfur atoms. Examples
of optionally substituted aryl groups include phenyl, methylphenyl,
naphthyl, anthryl, phenanthryl, and pyrenyl. Letter m is equal to 0
or 1, n is equal to 0, 1, 2 or 3, and 2 m+n is equal to 2 or 3.
[0069] In formula (L4), R.sup.L06 is an optionally substituted,
straight, branched or cyclic C.sub.1-C.sub.10 alkyl group or an
optionally substituted C.sub.6-C.sub.20 aryl group. Examples of
these groups are the same as exemplified for R.sup.L05. R.sup.L07
to R.sup.L16 independently represent hydrogen or monovalent
hydrocarbon groups of 1 to 15 carbon atoms. Exemplary hydrocarbon
groups are straight, branched or cyclic alkyl groups such as
methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl,
tert-amyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl,
cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl,
cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl and
cyclohexylbutyl, and substituted forms of these groups in which
some hydrogen atoms are replaced by hydroxyl, alkoxy, carboxy,
alkoxycarbonyl, oxo, amino, alkylamino, cyano, mercapto, alkylthio,
sulfo or other groups. Alternatively, R.sup.L07 to R.sup.L16 may
bond together to form a ring (for example, a pair of R.sup.L07 and
R.sup.L08, R.sup.L07 and R.sup.L09, R.sup.L08 and R.sup.L10,
R.sup.L09 and R.sup.L11 and R.sup.L12, R.sup.L13 and R.sup.L14, or
a similar pair form a ring). Each of R.sup.L07 to R.sup.L16
represents a divalent C.sub.1-C.sub.15 hydrocarbon group when they
form a ring, examples of which are those exemplified above for the
monovalent hydrocarbon groups, with one hydrogen atom being
eliminated. Two of R.sup.L07 to R.sup.L16 which are attached to
vicinal carbon atoms may bond together directly to form a double
bond (for example, a pair of R.sup.L07 and R.sup.L09, R.sup.L09 and
R.sup.L15, R.sup.L13 and R.sup.L15, or a similar pair).
[0070] Of the acid labile groups of formula (L1), the straight and
branched ones are exemplified by the following groups.
##STR00038##
[0071] Of the acid labile groups of formula (L1), the cyclic ones
are, for example, tetrahydrofuran-2-yl,
2-methyltetrahydrofuran-2-yl, tetrahydropyran-2-yl, and
2-methyltetrahydropyran-2-yl.
[0072] Examples of the acid labile groups of formula (L2) include
tert-butoxycarbonyl, tert-butoxycarbonylmethyl,
tert-amyloxycarbonyl, tert-amyloxycarbonylmethyl,
1,1-diethylpropyloxycarbonyl, 1,1-diethylpropyloxycarbonylmethyl,
1-ethylcyclopentyloxycarbonyl, 1-ethylcyclopentyloxycarbonylmethyl,
1-ethyl-2-cyclopentenyloxycarbonyl,
1-ethyl-2-cyclopentenyloxycarbonylmethyl,
1-ethoxyethoxycarbonylmethyl, 2-tetrahydropyranyloxycarbonylmethyl,
and 2-tetrahydrofuranyloxycarbonylmethyl groups.
[0073] Examples of the acid labile groups of formula (L3) include
1-methylcyclopentyl, 1-ethylcyclopentyl, 1-n-propylcyclopentyl,
1-isopropylcyclopentyl, 1-n-butylcyclopentyl,
1-sec-butylcyclopentyl, 1-cyclohexylcyclopentyl,
1-(4-methoxybutyl)cyclopentyl,
1-(bicyclo[2.2.1]heptan-2-yl)cyclopentyl,
1-(7-oxabicyclo[2.2.1]heptan-2-yl)cyclopentyl, 1-methylcyclohexyl,
1-ethylcyclohexyl, 1-methyl-2-cyclopentenyl,
1-ethyl-2-cyclopentenyl, 1-methyl-2-cyclohexenyl, and
1-ethyl-2-cyclohexenyl groups.
[0074] Of the acid labile groups of formula (L4), those groups of
the following formulae (L4-1) to (L4-4) are preferred.
##STR00039##
[0075] In formulas (L4-1) to (L4-4), the broken line denotes a
bonding site and direction. R.sup.L41 is each independently a
monovalent hydrocarbon group, typically a straight, branched or
cyclic C.sub.1-C.sub.10 alkyl group, such as methyl, ethyl, propyl,
isopropyl, n-butyl, sec-butyl, tert-butyl, tert-amyl, n-pentyl,
n-hexyl, cyclopentyl and cyclohexyl.
[0076] For formulas (L4-1) to (L4-4), there can exist enantiomers
and diastereomers. Each of formulae (L4-1) to (L4-4) collectively
represents all such stereoisomers. Such stereoisomers may be used
alone or in admixture.
[0077] For example, the general formula (L4-3) represents one or a
mixture of two or more selected from groups having the following
general formulas (L4-3-1) and (L4-3-2).
##STR00040##
[0078] Similarly, the general formula (L4-4) represents one or a
mixture of two or more selected from groups having the following
general formulas (L4-4-1) to (L4-4-4).
##STR00041##
[0079] Each of formulas (L4-1) to (L4-4), (L4-3-1) and (L4-3-2),
and (L4-4-1) to (L4-4-4) collectively represents an enantiomer
thereof and a mixture of enantiomers.
[0080] It is noted that in the above formulas (L4-1) to (L4-4),
(L4-3-1) and (L4-3-2), and (L4-4-1) to (L4-4-4), the bond direction
is on the exo side relative to the bicyclo[2.2.1]heptane ring,
which ensures high reactivity for acid catalyzed elimination
reaction (see JP-A 2000-336121). In preparing these monomers having
a tertiary exo-alkyl group of bicyclo[2.2.1]heptane skeleton as a
substituent group, there may be contained monomers substituted with
an endo-alkyl group as represented by the following formulas
(L4-1-endo) to (L4-4-endo). For good reactivity, an exo proportion
of at least 50 mol % is preferred, with an exo proportion of at
least 80 mol % being more preferred.
##STR00042##
[0081] (L4-1-endo) (L4-2-endo) (L4-3-endo) (L4-4-endo)
[0082] Illustrative examples of the acid labile group of formula
(L4) are given below
##STR00043##
[0083] Examples of the tertiary C.sub.4-C.sub.20 alkyl groups,
trialkylsilyl groups in which each alkyl moiety has 1 to 6 carbon
atoms, and C.sub.4-C.sub.20 oxoalkyl groups are as exemplified for
R.sup.L04 and the like.
[0084] In formula (R1), letters a1', a2', a3', b1', b2', b3', c1',
c2', c3', d1', d2', d3', and e' are numbers from 0 to less than 1
and indicate proportions of corresponding recurring units relative
to the entire recurring units of a polymer.
[0085] The polymer of the invention should preferably have a weight
average molecular weight of 1,000 to 500,000, more preferably 3,000
to 100,000, as measured by gel permeation chromatography (GPC)
versus polystyrene standards. Outside the range, there may arise
problems such as an extreme lowering of etching resistance and a
lowering of resolution due to a failure to have a difference in
dissolution rate before and after exposure.
[0086] In the polymers of the invention, the preferred proportion
of recurring units based on the respective monomers is in the
following range (in mol %), though not limited thereto. The
polymers contain: [0087] (I) from 5 mol % to 100 mol %, preferably
5 mol % to 60 mol % of constituent units having one or more of
formulae (1a) to (4c) derived from the monomers of formulae (1) to
(4), and [0088] (II) from 0 mol % to less than 100 mol %,
preferably 1 mol % to 95 mol %, and more preferably 40 mol % to 95
mol % of constituent units of one or more types in formula
(R1).
[0089] The polymers of the invention can be prepared through
copolymerization reaction using one or more compounds of formulae
(1) to (4) as a first monomer and compounds having a polymerizable
double bond as second and subsequent monomers. While a variety of
copolymerization reaction methods may be used in preparing the
polymers of the invention, radical polymerization, anionic
polymerization and coordination polymerization are preferred.
[0090] For radical polymerization, preferred reaction conditions
include (a) a solvent selected from among hydrocarbons such as
benzene, ethers such as tetrahydrofuran, alcohols such as ethanol,
ketones such as methyl isobutyl ketone and methyl ethyl ketone,
esters such as propylene glycol monomethyl ether acetate, propylene
glycol monoethyl ether acetate, and ethyl lactate, and lactones
such as .gamma.-butyrolactone, (b) a polymerization initiator
selected from azo compounds such as 2,2'-azobisisobutyronitrile and
peroxides such as benzoyl peroxide and lauroyl peroxide, (c) a
temperature of about 0.degree. C. to about 100.degree. C., and (d)
a time of about 0.5 to about 48 hours. Reaction conditions outside
the described range may be employed if desired.
[0091] For anionic polymerization, preferred reaction conditions
include (a) a solvent selected from among hydrocarbons such as
benzene, ethers such as tetrahydrofuran, and liquid ammonia, (b) a
polymerization initiator selected from metals such as sodium and
potassium, alkyl metals such as n-butyllithium and
sec-butyllithium, ketyl, and Grignard reagents, (c) a temperature
of about -78.degree. C. to about 0.degree. C., (d) a time of about
0.5 to about 48 hours, and (e) a stopper selected from among
proton-donative compounds such as methanol, halides such as methyl
iodide, and electrophilic compounds. Reaction conditions outside
the described range may be employed if desired.
[0092] For coordination polymerization, preferred reaction
conditions include (a) a solvent selected from among hydrocarbons
such as n-heptane and toluene, (b) a catalyst selected from
Ziegler-Natta catalysts comprising a transition metal (e.g.,
titanium) and alkylaluminum, Phillips catalysts of metal oxides
having chromium or nickel compounds carried thereon, and
olefin-metathesis mixed catalysts as typified by tungsten and
rhenium mixed catalysts, (c) a temperature of about 0.degree. C. to
about 100.degree. C., and (d) a time of about 0.5 to about 48
hours. Reaction conditions outside the described range may be
employed if desired.
Resist Composition
[0093] Since the polymer of the invention is useful as the base
resin of a resist composition, the other aspect of the invention
provides a resist composition, especially a chemically amplified
positive resist composition, comprising the polymer. Typically, the
resist composition contains the polymer, a photoacid generator, and
an organic solvent, and other optional components.
[0094] The polymer is not limited to one type and a mixture of two
or more polymers may be added. The use of plural polymers allows
for easy adjustment of resist properties.
Photoacid Generator
[0095] The resist composition of the invention also comprises a
compound which generates an acid in response to actinic light or
radiation (referred to as "photoacid generator"). The photoacid
generator may be any compound which generates an acid upon exposure
to high-energy radiation and specifically, any of well-known
photoacid generators which are commonly used in prior art resist
compositions, especially chemically amplified resist compositions.
Suitable photoacid generators include sulfonium salts, iodonium
salts, sulfonyldiazomethane, N-sulfonyloxyimide, and
oxime-O-sulfonate acid generators. Exemplary acid generators are
given below while they may be used alone or in admixture of two or
more.
[0096] Sulfonium salts are salts of sulfonium cations with
sulfonates, bis(substituted alkylsulfonyl)imides and
tris(substituted alkylsulfonyl)methides. Exemplary sulfonium
cations include triphenylsulfonium,
(4-tert-butoxyphenyl)diphenylsulfonium,
bis(4-tert-butoxyphenyl)phenylsulfonium,
tris(4-tert-butoxyphenyl)sulfonium,
(3-tert-butoxyphenyl)diphenylsulfonium,
bis(3-tert-butoxyphenyl)phenylsulfonium,
tris(3-tert-butoxyphenyl)sulfonium,
(3,4-di-tert-butoxyphenyl)diphenylsulfonium,
bis(3,4-di-tert-butoxyphenyl)phenylsulfonium,
tris(3,4-di-tert-butoxyphenyl)sulfonium,
diphenyl(4-thiophenoxyphenyl)sulfonium,
(4-tert-butoxycarbonylmethyloxyphenyl)diphenylsulfonium,
tris(4-tert-butoxycarbonylmethyloxyphenyl)sulfonium,
(4-tert-butoxyphenyl)bis(4-dimethylaminophenyl)sulfonium,
tris(4-dimethylaminophenyl)sulfonium, 2-naphthyldiphenylsulfonium,
dimethyl-2-naphthylsulfonium, 4-hydroxyphenyldimethylsulfonium,
4-methoxyphenyldimethylsulfonium, trimethylsulfonium,
2-oxocyclohexylcyclohexylmethylsulfonium, trinaphthylsulfonium,
tribenzylsulfonium, diphenylmethylsulfonium,
dimethylphenylsulfonium, 2-oxo-2-phenylethylthiacyclopentanium,
4-n-butoxynaphthyl-1-thiacyclopentanium, and
2-n-butoxynaphthyl-1-thiacyclopentanium. Exemplary sulfonates
include trifluoromethanesulfonate, pentafluoroethanesulfonate,
nonafluorobutanesulfonate, dodecafluorohexanesulfonate,
pentafluoroethylperfluorocyclohexanesulfonate,
heptadecafluorooctanesulfonate, 2,2,2-trifluoroethanesulfonate,
pentafluorobenzenesulfonate, 4-trifluoromethylbenzenesulfonate,
4-fluorobenzenesulfonate, mesitylenesulfonate,
2,4,6-triisopropylbenzenesulfonate, toluenesulfonate,
benzenesulfonate, 4-(4'-toluenesulfonyloxy)benzenesulfonate,
naphthalenesulfonate, camphorsulfonate, octanesulfonate,
dodecylbenzenesulfonate, butanesulfonate, methanesulfonate,
1,1-difluoro-2-naphthylethanesulfonate,
1,1,2,2-tetrafluoro-2-(norbornan-2-yl)ethanesulfonate,
1,1,2,2-tetrafluoro-2-(tetracyclo[4.4.0.1.sup.2,5.1.sup.7,10]dodec-3-en-8-
-yl)ethanesulfonate,
2-benzoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-(4-phenylbenzoyloxy)propanesulfonate,
1,1,3,3,3-pentafluoro-2-pivaloyloxypropanesulfonate,
2-cyclohexanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-furoyloxypropanesulfonate,
2-naphthoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-(4-tert-butylbenzoyloxy)-1,1,3,3,3-pentafluoropropane-sulfonate,
2-adamantanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-acetyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-hydroxypropanesulfonate,
1,1,3,3,3-pentafluoro-2-tosyloxypropanesulfonate,
adamantanemethoxycarbonyldifluoromethanesulfonate,
1-(3-hydroxymethyladamantane)methoxycarbonyldifluoromethane-sulfonate,
methoxycarbonyldifluoromethanesulfonate,
1-(hexahydro-2-oxo-3,5-methano-2H-cyclopenta[b]furan-6-yl-oxycarbonyl)dif-
luoromethanesulfonate, and
4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate. Exemplary
bis(substituted alkylsulfonyl)imides include
bistrifluoromethylsulfonylimide, bispentafluoroethylsulfonylimide,
bisheptafluoropropylsulfonylimide, and
perfluoro-1,3-propylenebissulfonylimide. A typical tris(substituted
alkylsulfonyl)methide is tristrifluoromethylsulfonylmethide.
Sulfonium salts based on combination of the foregoing examples are
included.
[0097] Iodonium salts are salts of iodonium cations with
sulfonates, bis(substituted alkylsulfonyl)imides and
tris(substituted alkylsulfonyl)methides. Exemplary iodonium cations
are aryliodonium cations including diphenyliodonium,
bis(4-tert-butylphenyl)iodonium, 4-tert-butoxyphenylphenyliodonium,
and 4-methoxyphenylphenyliodonium. Exemplary sulfonates include
trifluoromethanesulfonate, pentafluoroethanesulfonate,
nonafluorobutanesulfonate, dodecafluorohexanesulfonate,
pentafluoroethylperfluorocyclohexanesulfonate,
heptadecafluorooctanesulfonate, 2,2,2-trifluoroethanesulfonate,
pentafluorobenzenesulfonate, 4-trifluoromethylbenzenesulfonate,
4-fluorobenzenesulfonate, mesitylenesulfonate,
2,4,6-triisopropylbenzenesulfonate, toluenesulfonate,
benzenesulfonate, 4-(4-toluenesulfonyloxy)benzenesulfonate,
naphthalenesulfonate, camphorsulfonate, octanesulfonate,
dodecylbenzenesulfonate, butanesulfonate, methanesulfonate,
1,1-difluoro-2-naphthylethanesulfonate,
1,1,2,2-tetrafluoro-2-(norbornan-2-yl)ethanesulfonate,
1,1,2,2-tetrafluoro-2-(tetracyclo[4.4.0.1.sup.2,5.1.sup.7,10]dodec-3-en-8-
-yl)ethanesulfonate,
2-benzoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-(4-phenylbenzoyloxy)propanesulfonate,
1,1,3,3,3-pentafluoro-2-pivaloyloxypropanesulfonate,
2-cyclohexanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-furoyloxypropanesulfonate,
2-naphthoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-(4-tert-butylbenzoyloxy)-1,1,3,3,3-pentafluoropropane-sulfonate,
2-adamantanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-acetyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-hydroxypropanesulfonate,
1,1,3,3,3-pentafluoro-2-tosyloxypropanesulfonate,
adamantanemethoxycarbonyldifluoromethanesulfonate,
1-(3-hydroxymethyladamantane)methoxycarbonyldifluoromethane-sulfonate,
methoxycarbonyldifluoromethanesulfonate,
1-(hexahydro-2-oxo-3,5-methano-2H-cyclopenta[b]furan-6-yl-oxycarbonyl)dif-
luoromethanesulfonate, and
4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate. Exemplary
bis(substituted alkylsulfonyl)imides include
bistrifluoromethylsulfonylimide, bispentafluoroethylsulfonylimide,
bisheptafluoropropylsulfonylimide, and
perfluoro-1,3-propylenebissulfonylimide.
A typical tris(substituted alkylsulfonyl)methide is
tristrifluoromethylsulfonylmethide. Iodonium salts based on
combination of the foregoing examples are included.
[0098] Exemplary sulfonyldiazomethane compounds include
bissulfonyldiazomethane compounds and sulfonylcarbonyldiazomethane
compounds such as bis(ethylsulfonyl)diazomethane,
bis(1-methylpropylsulfonyl)diazomethane,
bis(2-methylpropylsulfonyl)diazomethane,
bis(1,1-dimethylethylsulfonyl)diazomethane,
bis(cyclohexylsulfonyl)diazomethane,
bis(perfluoroisopropylsulfonyl)diazomethane,
bis(phenylsulfonyl)diazomethane,
bis(4-methylphenylsulfonyl)diazomethane,
bis(2,4-dimethylphenylsulfonyl)diazomethane,
bis(2-naphthylsulfonyl)diazomethane,
bis(4-acetyloxyphenylsulfonyl)diazomethane,
bis(4-methanesulfonyloxyphenylsulfonyl)diazomethane,
bis(4-(4-toluenesulfonyloxy)phenylsulfonyl)diazomethane,
bis(4-(n-hexyloxy)phenylsulfonyl)diazomethane,
bis(2-methyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,
bis(2,5-dimethyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,
bis(3,5-dimethyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,
bis(2-methyl-5-isopropyl-4-(n-hexyloxy)phenylsulfonyl)-diazomethane,
4-methylphenylsulfonylbenzoyldiazomethane,
tert-butylcarbonyl-4-methylphenylsulfonyldiazomethane,
2-naphthylsulfonylbenzoyldiazomethane,
4-methylphenylsulfonyl-2-naphthoyldiazomethane,
methylsulfonylbenzoyldiazomethane, and
tert-butoxycarbonyl-4-methylphenylsulfonyldiazomethane.
[0099] N-sulfonyloxyimide photoacid generators include combinations
of imide skeletons with sulfonates. Exemplary imide skeletons are
succinimide, naphthalene dicarboxylic acid imide, phthalimide,
cyclohexyldicarboxylic acid imide, 5-norbornene-2,3-dicarboxylic
acid imide, and 7-oxabicyclo[2.2.1]-5-heptene-2,3-dicarboxylic acid
imide. Exemplary sulfonates include trifluoromethanesulfonate,
pentafluoroethanesulfonate, nonafluorobutanesulfonate,
dodecafluorohexanesulfonate,
pentafluoroethylperfluorocyclohexanesulfonate,
heptadecafluorooctanesulfonate, 2,2,2-trifluoroethanesulfonate,
pentafluorobenzenesulfonate, 4-trifluoromethylbenzenesulfonate,
4-fluorobenzenesulfonate, mesitylenesulfonate,
2,4,6-triisopropylbenzenesulfonate, toluenesulfonate,
benzenesulfonate, naphthalenesulfonate, camphorsulfonate,
octanesulfonate, dodecylbenzenesulfonate, butanesulfonate,
methanesulfonate, 1,1-difluoro-2-naphthylethanesulfonate,
1,1,2,2-tetrafluoro-2-(norbornan-2-yl)ethanesulfonate,
1,1,2,2-tetrafluoro-2-(tetracyclo[4.4.0.1.sup.2,5.1.sup.7,10]dodec-3-en-8-
-yl)ethanesulfonate,
2-benzoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-(4-phenylbenzoyloxy)propanesulfonate,
1,1,3,3,3-pentafluoro-2-pivaloyloxypropanesulfonate,
2-cyclohexanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-furoyloxypropanesulfonate,
2-naphthoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-(4-tert-butylbenzoyloxy)-1,1,3,3,3-pentafluoropropane-sulfonate,
2-adamantanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-acetyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-hydroxypropanesulfonate,
1,1,3,3,3-pentafluoro-2-tosyloxypropanesulfonate,
adamantanemethoxycarbonyldifluoromethanesulfonate,
1-(3-hydroxymethyladamantane)methoxycarbonyldifluoromethane-sulfonate,
methoxycarbonyldifluoromethanesulfonate,
1-(hexahydro-2-oxo-3,5-methano-2H-cyclopenta[b]furan-6-yl-oxycarbonyl)dif-
luoromethanesulfonate, and
4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate.
[0100] Benzoinsulfonate photoacid generators include benzoin
tosylate, benzoin mesylate, and benzoin butanesulfonate.
[0101] Pyrogallol trisulfonate photoacid generators include
pyrogallol, phloroglucinol, catechol, resorcinol, and hydroquinone,
in which all the hydroxyl groups are substituted by
trifluoromethanesulfonate, pentafluoroethanesulfonate,
nonafluorobutanesulfonate, dodecafluorohexanesulfonate,
pentafluoroethylperfluorocyclohexanesulfonate,
heptadecafluorooctanesulfonate, 2,2,2-trifluoroethanesulfonate,
pentafluorobenzenesulfonate, 4-trifluoromethylbenzenesulfonate,
4-fluorobenzenesulfonate, toluenesulfonate, benzenesulfonate,
naphthalenesulfonate, camphorsulfonate, octanesulfonate,
dodecylbenzenesulfonate, butanesulfonate, methanesulfonate,
1,1-difluoro-2-naphthylethanesulfonate,
1,1,2,2-tetrafluoro-2-(norbornan-2-yl)ethanesulfonate,
1,1,2,2-tetrafluoro-2-(tetracyclo[4.4.0.1.sup.2,5.1.sup.7,10]dodec-3-en-8-
-yl)ethanesulfonate,
2-benzoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-(4-phenylbenzoyloxy)propanesulfonate,
1,1,3,3,3-pentafluoro-2-pivaloyloxypropanesulfonate,
2-cyclohexanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-furoyloxypropanesulfonate,
2-naphthoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-(4-tert-butylbenzoyloxy)-1,1,3,3,3-pentafluoropropane-sulfonate,
2-adamantanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-acetyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-hydroxypropanesulfonate,
1,1,3,3,3-pentafluoro-2-tosyloxypropanesulfonate,
adamantanemethoxycarbonyldifluoromethanesulfonate,
1-(3-hydroxymethyladamantane)methoxycarbonyldifluoromethane-sulfonate,
methoxycarbonyldifluoromethanesulfonate,
1-(hexahydro-2-oxo-3,5-methano-2H-cyclopenta[b]furan-6-yl-oxycarbonyl)dif-
luoromethanesulfonate, and
4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate.
[0102] Nitrobenzyl sulfonate photoacid generators include
2,4-dinitrobenzyl sulfonate, 2-nitrobenzyl sulfonate, and
2,6-dinitrobenzyl sulfonate, with exemplary sulfonates including
trifluoromethanesulfonate, pentafluoroethanesulfonate,
nonafluorobutanesulfonate, dodecafluorohexanesulfonate,
pentafluoroethylperfluorocyclohexanesulfonate,
heptadecafluorooctanesulfonate, 2,2,2-trifluoroethanesulfonate,
pentafluorobenzenesulfonate, 4-trifluoromethylbenzenesulfonate,
4-fluorobenzenesulfonate, toluenesulfonate, benzenesulfonate,
naphthalenesulfonate, camphorsulfonate, octanesulfonate,
dodecylbenzenesulfonate, butanesulfonate, methanesulfonate,
1,1-difluoro-2-naphthylethanesulfonate,
1,1,2,2-tetrafluoro-2-(norbornan-2-yl)ethanesulfonate,
1,1,2,2-tetrafluoro-2-(tetracyclo[4.4.0.1.sup.2,5.1.sup.7,10]dodec-3-en-8-
-yl)ethanesulfonate,
2-benzoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-(4-phenylbenzoyloxy)propanesulfonate,
1,1,3,3,3-pentafluoro-2-pivaloyloxypropanesulfonate,
2-cyclohexanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-furoyloxypropanesulfonate,
2-naphthoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-(4-tert-butylbenzoyloxy)-1,1,3,3,3-pentafluoropropane-sulfonate,
2-adamantanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-acetyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-hydroxypropanesulfonate,
1,1,3,3,3-pentafluoro-2-tosyloxypropanesulfonate,
adamantanemethoxycarbonyldifluoromethanesulfonate,
1-(3-hydroxymethyladamantane)methoxycarbonyldifluoromethane-sulfonate,
methoxycarbonyldifluoromethanesulfonate,
1-(hexahydro-2-oxo-3,5-methano-2H-cyclopenta[b]furan-6-yl-oxycarbonyl)dif-
luoromethanesulfonate, and
4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate. Also useful
are analogous nitrobenzyl sulfonate compounds in which the nitro
group on the benzyl side is substituted by a trifluoromethyl
group.
[0103] Sulfone photoacid generators include
bis(phenylsulfonyl)methane, bis(4-methylphenylsulfonyl)methane,
bis(2-naphthylsulfonyl)methane, 2,2-bis(phenylsulfonyl)propane,
2,2-bis(4-methylphenylsulfonyl)propane,
2,2-bis(2-naphthylsulfonyl)propane,
2-methyl-2-(p-toluenesulfonyl)propiophenone,
2-cyclohexylcarbonyl-2-(p-toluenesulfonyl)propane, and
2,4-dimethyl-2-(p-toluenesulfonyl)pentan-3-one.
[0104] Photoacid generators in the form of glyoxime derivatives are
described in Japanese Patent No. 2,906,999 and JP-A 9-301948 and
include bis-O-(p-toluenesulfonyl)-.alpha.-dimethylglyoxime,
bis-O-(p-toluenesulfonyl)-.alpha.-diphenylglyoxime,
bis-O-(p-toluenesulfonyl)-.alpha.-dicyclohexylglyoxime,
bis-O-(p-toluenesulfonyl)-2,3-pentanedioneglyoxime,
bis-O-(n-butanesulfonyl)-.alpha.-dimethylglyoxime,
bis-O-(n-butanesulfonyl)-.alpha.-diphenylglyoxime,
bis-O-(n-butanesulfonyl)-.alpha.-dicyclohexylglyoxime,
bis-O-(methanesulfonyl)-.alpha.-dimethylglyoxime,
bis-O-(trifluoromethanesulfonyl)-.alpha.-dimethylglyoxime,
bis-O-(2,2,2-trifluoroethanesulfonyl)-.alpha.-dimethylglyoxime,
bis-O-(10-camphorsulfonyl)-.alpha.-dimethylglyoxime,
bis-O-(benzenesulfonyl)-.alpha.-dimethylglyoxime,
bis-O-(p-fluorobenzenesulfonyl)-.alpha.-dimethylglyoxime,
bis-O-(p-trifluoromethylbenzenesulfonyl)-.alpha.-dimethylglyoxime,
bis-O-(xylenesulfonyl)-.alpha.-dimethylglyoxime,
bis-O-(trifluoromethanesulfonyl)-nioxime,
bis-O-(2,2,2-trifluoroethanesulfonyl)-nioxime,
bis-O-(10-camphorsulfonyl)-nioxime,
bis-O-(benzenesulfonyl)-nioxime,
bis-O-(p-fluorobenzenesulfonyl)-nioxime,
bis-O-(p-trifluoromethylbenzenesulfonyl)-nioxime, and
bis-O-(xylenesulfonyl)-nioxime. Also included are compounds of the
foregoing skeleton having substituted thereon
2-benzoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-(4-phenylbenzoyloxy)propanesulfonate,
1,1,3,3,3-pentafluoro-2-pivaloyloxypropanesulfonate,
2-cyclohexanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-furoyloxypropanesulfonate,
2-naphthoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-(4-tert-butylbenzoyloxy)-1,1,3,3,3-pentafluoropropane-sulfonate,
2-adamantanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-acetyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-hydroxypropanesulfonate,
1,1,3,3,3-pentafluoro-2-tosyloxypropanesulfonate,
adamantanemethoxycarbonyldifluoromethanesulfonate,
1-(3-hydroxymethyladamantane)methoxycarbonyldifluoromethane-sulfonate,
methoxycarbonyldifluoromethanesulfonate,
1-(hexahydro-2-oxo-3,5-methano-2H-cyclopenta[b]furan-6-yl-oxycarbonyl)dif-
luoromethanesulfonate, and
4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate.
[0105] Also included are the oxime sulfonates described in U.S.
Pat. No. 6,004,724, for example,
(5-(4-toluenesulfonyl)oxyimino-5H-thiophen-2-ylidene)phenyl-acetonitrile,
(5-(10-camphorsulfonyl)oxyimino-5H-thiophen-2-ylidene)phenyl-acetonitrile-
,
(5-n-octanesulfonyloxyimino-5H-thiophen-2-ylidene)phenyl-acetonitrile,
(5-(4-toluenesulfonyl)oxyimino-5H-thiophen-2-ylidene)(2-methylphenyl)acet-
onitrile,
(5-(10-camphorsulfonyl)oxyimino-5H-thiophen-2-ylidene)(2-methylp-
henyl)acetonitrile,
(5-n-octanesulfonyloxyimino-5H-thiophen-2-ylidene)(2-methylphenyl)acetoni-
trile, etc.
Also included are the oxime sulfonates described in U.S. Pat. No.
6,916,591, for example,
(5-(4-(4-toluenesulfonyloxy)benzenesulfonyl)oxyimino-5H-thiophen-2-yliden-
e)phenylacetonitrile and
(5-(2,5-bis(4-toluenesulfonyloxy)benzenesulfonyl)oxyimino-5H-thiophen-2-y-
lidene)phenylacetonitrile. Also included are compounds of the
foregoing skeleton having substituted thereon
2-benzoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-(4-phenylbenzoyloxy)propanesulfonate,
1,1,3,3,3-pentafluoro-2-pivaloyloxypropanesulfonate,
2-cyclohexanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-furoyloxypropanesulfonate,
2-naphthoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-(4-tert-butylbenzoyloxy)-1,1,3,3,3-pentafluoropropane-sulfonate,
2-adamantanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-acetyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-hydroxypropanesulfonate,
1,1,3,3,3-pentafluoro-2-tosyloxypropanesulfonate,
adamantanemethoxycarbonyldifluoromethanesulfonate,
1-(3-hydroxymethyladamantane)methoxycarbonyldifluoromethane-sulfonate,
methoxycarbonyldifluoromethanesulfonate,
1-(hexahydro-2-oxo-3,5-methano-2H-cyclopenta[b]furan-6-yl-oxycarbonyl)dif-
luoromethanesulfonate, and
4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate.
[0106] Also included are the oxime sulfonates described in U.S.
Pat. No. 6,261,738 and JP-A 2000-314956, for example,
2,2,2-trifluoro-1-phenyl-ethanone oxime-O-methylsulfonate;
2,2,2-trifluoro-1-phenyl-ethanone oxime-O-(10-camphoryl-sulfonate);
2,2,2-trifluoro-1-phenyl-ethanone
oxime-O-(4-methoxyphenylsulfonate);
2,2,2-trifluoro-1-phenyl-ethanone oxime-O-(1-naphthylsulfonate);
2,2,2-trifluoro-1-phenyl-ethanone oxime-O-(2-naphthylsulfonate);
2,2,2-trifluoro-1-phenyl-ethanone
oxime-O-(2,4,6-trimethylphenylsulfonate);
2,2,2-trifluoro-1-(4-methylphenyl)-ethanone
oxime-O-(10-camphorylsulfonate);
2,2,2-trifluoro-1-(4-methylphenyl)-ethanone
oxime-O-(methylsulfonate);
2,2,2-trifluoro-1-(2-methylphenyl)-ethanone
oxime-O-(10-camphorylsulfonate);
2,2,2-trifluoro-1-(2,4-dimethylphenyl)-ethanone
oxime-O-(10-camphorylsulfonate);
2,2,2-trifluoro-1-(2,4-dimethylphenyl)-ethanone
oxime-O-(1-naphthylsulfonate);
2,2,2-trifluoro-1-(2,4-dimethylphenyl)-ethanone
oxime-O-(2-naphthylsulfonate);
2,2,2-trifluoro-1-(2,4,6-trimethylphenyl)-ethanone oxime-O
-(10-camphorylsulfonate);
2,2,2-trifluoro-1-(2,4,6-trimethylphenyl)-ethanone
oxime-O-(1-naphthylsulfonate);
2,2,2-trifluoro-1-(2,4,6-trimethylphenyl)-ethanone oxime-O
-(2-naphthylsulfonate);
2,2,2-trifluoro-1-(4-methoxyphenyl)-ethanone
oxime-O-methylsulfonate;
2,2,2-trifluoro-1-(4-methylthiophenyl)-ethanone
oxime-O-methylsulfonate;
2,2,2-trifluoro-1-(3,4-dimethoxyphenyl)-ethanone
oxime-O-methylsulfonate;
2,2,3,3,4,4,4-heptafluoro-1-phenyl-butanone
oxime-O-(10-camphorylsulfonate);
2,2,2-trifluoro-1-(phenyl)-ethanone oxime-O-methylsulfonate;
2,2,2-trifluoro-1-(phenyl)-ethanone oxime-O-10-camphorylsulfonate;
2,2,2-trifluoro-1-(phenyl)-ethanone
oxime-O-(4-methoxyphenyl)sulfonate;
2,2,2-trifluoro-1-(phenyl)-ethanone oxime-O-(1-naphthyl)-sulfonate;
2,2,2-trifluoro-1-(phenyl)-ethanone oxime-O-(2-naphthyl)sulfonate;
2,2,2-trifluoro-1-(phenyl)-ethanone
oxime-O-(2,4,6-trimethylphenyl)sulfonate;
2,2,2-trifluoro-1-(4-methylphenyl)-ethanone
oxime-O-(10-camphoryl)sulfonate;
2,2,2-trifluoro-1-(4-methylphenyl)-ethanone
oxime-O-methylsulfonate;
2,2,2-trifluoro-1-(2-methylphenyl)-ethanone
oxime-O-(10-camphoryl)sulfonate;
2,2,2-trifluoro-1-(2,4-dimethylphenyl)-ethanone
oxime-O-(1-naphthyl)sulfonate;
2,2,2-trifluoro-1-(2,4-dimethylphenyl)-ethanone
oxime-O-(2-naphthyl)sulfonate;
2,2,2-trifluoro-1-(2,4,6-trimethyl-phenyl)-ethanone
oxime-O-(10-camphoryl)sulfonate;
2,2,2-trifluoro-1-(2,4,6-trimethylphenyl)-ethanone
oxime-O-(1-naphthyl)sulfonate;
2,2,2-trifluoro-1-(2,4,6-trimethyl-phenyl)-ethanone
oxime-O-(2-naphthyl)sulfonate;
2,2,2-trifluoro-1-(4-methoxyphenyl)-ethanone
oxime-O-methylsulfonate;
2,2,2-trifluoro-1-(4-thiomethylphenyl)-ethanone
oxime-O-methylsulfonate;
2,2,2-trifluoro-1-(3,4-dimethoxyphenyl)-ethanone
oxime-O-methylsulfonate;
2,2,2-trifluoro-1-(4-methoxyphenyl)-ethanone
oxime-O-(4-methylphenyl)sulfonate;
2,2,2-trifluoro-1-(4-methoxyphenyl)-ethanone
oxime-O-(4-methoxyphenyl)sulfonate;
2,2,2-trifluoro-1-(4-methoxyphenyl)-ethanone
oxime-O-(4-dodecylphenyl)-sulfonate;
2,2,2-trifluoro-1-(4-methoxyphenyl)-ethanone
oxime-O-octylsulfonate;
2,2,2-trifluoro-1-(4-thiomethyl-phenyl)-ethanone
oxime-O-(4-methoxyphenyl)sulfonate;
2,2,2-trifluoro-1-(4-thiomethylphenyl)-ethanone
oxime-O-(4-dodecylphenyl)sulfonate;
2,2,2-trifluoro-1-(4-thiomethyl-phenyl)-ethanone
oxime-O-octylsulfonate;
2,2,2-trifluoro-1-(4-thiomethylphenyl)-ethanone
oxime-O-(2-naphthyl)sulfonate;
2,2,2-trifluoro-1-(2-methylphenyl)-ethanone
oxime-O-methylsulfonate; 2,2,2-trifluoro-1-(4-methylphenyl)ethanone
oxime-O-phenylsulfonate;
2,2,2-trifluoro-1-(4-chlorophenyl)-ethanone
oxime-O-phenylsulfonate;
2,2,3,3,4,4,4-heptafluoro-1-(phenyl)-butanone
oxime-O-(10-camphoryl)sulfonate;
2,2,2-trifluoro-1-naphthyl-ethanone oxime-O-methylsulfonate;
2,2,2-trifluoro-2-naphthyl-ethanone oxime-O-methylsulfonate;
2,2,2-trifluoro-1-[4-benzylphenyl]-ethanone
oxime-O-methylsulfonate;
2,2,2-trifluoro-1-[4-(phenyl-1,4-dioxa-but-1-yl)phenyl]-ethanone
oxime-O-methylsulfonate; 2,2,2-trifluoro-1-naphthyl-ethanone
oxime-O-propylsulfonate; 2,2,2-trifluoro-2-naphthyl-ethanone
oxime-O-propylsulfonate;
2,2,2-trifluoro-1-[4-benzylphenyl]-ethanone
oxime-O-propyl-sulfonate;
2,2,2-trifluoro-1-[4-methylsulfonylphenyl]-ethanone
oxime-O-propylsulfonate;
1,3-bis[1-(4-phenoxy-phenyl)-2,2,2-trifluoroethanone
oxime-O-sulfonyl]phenyl;
2,2,2-trifluoro-1-[4-methylsulfonyloxyphenyl]-ethanone
oxime-O-propylsulfonate;
2,2,2-trifluoro-1-[4-methylcarbonyloxy-phenyl]-ethanone
oxime-O-propylsulfonate;
2,2,2-trifluoro-1-[6H,7H-5,8-dioxonaphth-2-yl]-ethanone
oxime-O-propyl-sulfonate;
2,2,2-trifluoro-1-[4-methoxycarbonyl-methoxyphenyl]-ethanone
oxime-O-propylsulfonate;
2,2,2-trifluoro-1-[4-(methoxycarbonyl)-(4-amino-1-oxa-pent-1-yl)-phenyl]--
ethanone oxime-O-propylsulfonate;
2,2,2-trifluoro-1-[3,5-dimethyl-4-ethoxyphenyl]-ethanone
oxime-O-propylsulfonate;
2,2,2-trifluoro-1-[4-benzyloxyphenyl]-ethanone
oxime-O-propylsulfonate; 2,2,2-trifluoro-1-[2-thiophenyl]-ethanone
oxime-O-propylsulfonate;
2,2,2-trifluoro-1-[1-dioxa-thiophen-2-yl)]-ethanone
oxime-O-propylsulfonate;
2,2,2-trifluoro-1-(4-(3-(4-(2,2,2-trifluoro-1-(trifluoromethanesulfonylox-
yimino)-ethyl)-phenoxy)-propoxy)-phenyl)ethanone
oxime(trifluoromethane-sulfonate);
2,2,2-trifluoro-1-(4-(3-(4-(2,2,2-trifluoro-1-(1-propanesulfonyloxyimino)-
-ethyl)-phenoxy)-propoxy)-phenyl)-ethanone
oxime(1-propanesulfonate); and
2,2,2-trifluoro-1-(4-(3-(4-(2,2,2-trifluoro-1-(1-butanesulfonyloxyimino)--
ethyl)-phenoxy)-propoxy)-phenyl)ethanone oxime(1-butanesulfonate).
Also included are the oxime sulfonates described in U.S. Pat. No.
6,916,591, for example,
2,2,2-trifluoro-1-(4-(3-(4-(2,2,2-trifluoro-1-(4-(4-methylphenylsulfonylo-
xy)-phenylsulfonyloxyimino)-ethyl)-phenoxy)-propoxy)-phenyl)ethanone
oxime(4-(4-methylphenylsulfonyloxy)-phenylsulfonate) and
2,2,2-trifluoro-1-(4-(3-(4-(2,2,2-trifluoro-1-(2,5-bis(4-methylphenylsulf-
onyloxy)-benzenesulfonyloxy)phenylsulfonyloxyimino)-ethyl)-phenoxy)-propox-
y)-phenyl)ethanone
oxime(2,5-bis(4-methylphenyl-sulfonyloxy)benzenesulfonyloxy)phenylsulfona-
te). Also included are compounds of the foregoing skeleton having
substituted thereon
2-benzoyloxy-1,1,3,3,3-pentafluoro-propanesulfonate,
1,1,3,3,3-pentafluoro-2-(4-phenylbenzoyl-oxy)propanesulfonate,
1,1,3,3,3-pentafluoro-2-pivaloyloxy-propanesulfonate,
2-cyclohexanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-furoyloxypropanesulfonate,
2-naphthoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-(4-tert-butylbenzoyloxy)-1,1,3,3,3-pentafluoropropanesulfonate,
2-adamantane-carbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-acetyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-hydroxypropanesulfonate,
1,1,3,3,3-pentafluoro-2-tosyloxypropanesulfonate,
adamantanemethoxycarbonyldifluoromethanesulfonate,
1-(3-hydroxymethyladamantane)methoxycarbonyldifluoro-methanesulfonate,
methoxycarbonyldifluoromethanesulfonate,
1-(hexahydro-2-oxo-3,5-methano-2H-cyclopenta[b]furan-6-yl-oxycarbonyl)dif-
luoromethanesulfonate, and
4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate.
[0107] Also included are the oxime sulfonates described in JP-A
9-95479 and JP-A 9-230588 and the references cited therein, for
example, .alpha.-(p-toluenesulfonyloxyimino)-phenylacetonitrile,
.alpha.-(p-chlorobenzenesulfonyloxyimino)-phenylacetonitrile,
.alpha.-(4-nitrobenzenesulfonyloxyimino)-phenylacetonitrile,
.alpha.-(4-nitro-2-trifluoromethylbenzenesulfonyloxyimino)-phenylacetonit-
rile, .alpha.-(benzenesulfonyloxyimino)-4-chlorophenylacetonitrile,
.alpha.-(benzenesulfonyloxyimino)-2,4-dichlorophenylacetonitrile,
.alpha.-(benzenesulfonyloxyimino)-2,6-dichlorophenylacetonitrile,
.alpha.-(benzenesulfonyloxyimino)-4-methoxyphenylacetonitrile,
.alpha.-(2-chlorobenzenesulfonyloxyimino)-4-methoxyphenyl-acetonitrile,
.alpha.-(benzenesulfonyloxyimino)-2-thienylacetonitrile,
.alpha.-(4-dodecylbenzenesulfonyloxyimino)-phenylacetonitrile,
.alpha.-[(4-toluenesulfonyloxyimino)-4-methoxyphenyl]acetonitrile,
.alpha.-[(dodecylbenzenesulfonyloxyimino)-4-methoxyphenyl]-acetonitrile,
.alpha.-(tosyloxyimino)-3-thienylacetonitrile,
.alpha.-(methylsulfonyloxyimino)-1-cyclopentenylacetonitrile,
.alpha.-(ethylsulfonyloxyimino)-1-cyclopentenylacetonitrile,
.alpha.-(isopropylsulfonyloxyimino)-1-cyclopentenylacetonitrile,
.alpha.-(n-butylsulfonyloxyimino)-1-cyclopentenylacetonitrile,
.alpha.-(ethylsulfonyloxyimino)-1-cyclohexenylacetonitrile,
.alpha.-(isopropylsulfonyloxyimino)-1-cyclohexenylacetonitrile, and
.alpha.-(n-butylsulfonyloxyimino)-1-cyclohexenylacetonitrile.
Also included are compounds of the foregoing skeleton having
substituted thereon
2-benzoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-(4-phenylbenzoyloxy)propanesulfonate,
1,1,3,3,3-pentafluoro-2-pivaloyloxypropanesulfonate,
2-cyclohexanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-furoyloxypropanesulfonate,
2-naphthoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-(4-tert-butylbenzoyloxy)-1,1,3,3,3-pentafluoropropane-sulfonate,
2-adamantanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-acetyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-hydroxypropanesulfonate,
1,1,3,3,3-pentafluoro-2-tosyloxypropanesulfonate,
adamantanemethoxycarbonyldifluoromethanesulfonate,
1-(3-hydroxymethyladamantane)methoxycarbonyldifluoromethane-sulfonate,
methoxycarbonyldifluoromethanesulfonate,
1-(hexahydro-2-oxo-3,5-methano-2H-cyclopenta[b]furan-6-yl-oxycarbonyl)dif-
luoromethanesulfonate, and
4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate.
[0108] Also included are oxime sulfonates having the formula:
##STR00044##
Wherein R.sup.s1 is a substituted or unsubstituted
haloalkylsulfonyl or halobenzenesulfonyl group of 1 to 10 carbon
atoms, R.sup.s2 is a haloalkyl group of 1 to 11 carbon atoms, and
Ar.sup.s1 is substituted or unsubstituted aromatic or
hetero-aromatic group, as described in WO 2004/074242. Examples
include
2-[2,2,3,3,4,4,5,5-octafluoro-1-(nonafluoro-butylsulfonyloxyimino)-pentyl-
]-fluorene,
2-[2,2,3,3,4,4-pentafluoro-1-(nonafluorobutylsulfonyloxy-imino)-butyl]-fl-
uorene,
2-[2,2,3,3,4,4,5,5,6,6-decafluoro-1-(nonafluorobutylsulfonyl-oxyim-
ino)-hexyl]-fluorene,
2-[2,2,3,3,4,4,5,5-octafluoro-1-(nonafluorobutylsulfonyloxy-imino)-pentyl-
]-4-biphenyl,
2-[2,2,3,3,4,4-pentafluoro-1-(nonafluorobutylsulfonyloxy-imino)-butyl]-4--
biphenyl, and
2-[2,2,3,3,4,4,5,5,6,6-decafluoro-1-(nonafluorobutylsulfonyl-oxyimino)-he-
xyl]-4-biphenyl. Also included are compounds of the foregoing
skeleton having substituted thereon
2-benzoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-(4-phenylbenzoyloxy)propanesulfonate,
1,1,3,3,3-pentafluoro-2-pivaloyloxypropanesulfonate,
2-cyclohexanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-furoyloxypropanesulfonate,
2-naphthoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-(4-tert-butylbenzoyloxy)-1,1,3,3,3-pentafluoropropane-sulfonate,
2-adamantanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-acetyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-hydroxypropanesulfonate,
1,1,3,3,3-pentafluoro-2-tosyloxypropanesulfonate,
adamantanemethoxycarbonyldifluoromethanesulfonate,
1-(3-hydroxymethyladamantane)methoxycarbonyldifluoromethane-sulfonate,
methoxycarbonyldifluoromethanesulfonate,
1-(hexahydro-2-oxo-3,5-methano-2H-cyclopenta[b]furan-6-yl-oxycarbonyl)dif-
luoromethanesulfonate, and
4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate.
[0109] Suitable bisoxime sulfonates include those described in JP-A
9-208554, for example,
bis(.alpha.-(4-toluenesulfonyloxy)imino)-p-phenylenediacetonitrile,
bis(.alpha.-(benzenesulfonyloxy)imino)-p-phenylenediacetonitrile,
bis(.alpha.-(methanesulfonyloxy)imino)-p-phenylenediacetonitrile,
bis(.alpha.-(butanesulfonyloxy)imino)-p-phenylenediacetonitrile,
bis(.alpha.-(10-camphorsulfonyloxy)imino)-p-phenylenediacetonitrile,
bis(.alpha.-(4-toluenesulfonyloxy)imino)-p-phenylenediacetonitrile,
bis(.alpha.-(trifluoromethanesulfonyloxy)imino)-p-phenylenediaceto-nitril-
e,
bis(.alpha.-(4-methoxybenzenesulfonyloxy)imino)-p-phenylenediaceto-nitr-
ile,
bis(.alpha.-(4-toluenesulfonyloxy)imino)-m-phenylenediacetonitrile,
bis(.alpha.-(benzenesulfonyloxy)imino)-m-phenylenediacetonitrile,
bis(.alpha.-(methanesulfonyloxy)imino)-m-phenylenediacetonitrile,
bis(.alpha.-(butanesulfonyloxy)imino)-m-phenylenediacetonitrile,
bis(.alpha.-(10-camphorsulfonyloxy)imino)-m-phenylenediacetonitrile,
bis(.alpha.-(4-toluenesulfonyloxy)imino)-m-phenylenediacetonitrile,
bis(.alpha.-(trifluoromethanesulfonyloxy)imino)-m-phenylenediaceto-nitril-
e, and
bis(.alpha.-(4-methoxybenzenesulfonyloxy)imino)-m-phenylenediaceto--
nitrile.
[0110] Also included are compounds of the foregoing skeleton having
substituted thereon
2-benzoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-(4-phenylbenzoyloxy)propanesulfonate,
1,1,3,3,3-pentafluoro-2-pivaloyloxypropanesulfonate,
2-cyclohexanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-furoyloxypropanesulfonate,
2-naphthoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-(4-tert-butylbenzoyloxy)-1,1,3,3,3-pentafluoropropane-sulfonate,
2-adamantanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-acetyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
1,1,3,3,3-pentafluoro-2-hydroxypropanesulfonate,
1,1,3,3,3-pentafluoro-2-tosyloxypropanesulfonate,
adamantanemethoxycarbonyldifluoromethanesulfonate,
1-(3-hydroxymethyladamantane)methoxycarbonyldifluoromethane-sulfonate,
methoxycarbonyldifluoromethanesulfonate,
1-(hexahydro-2-oxo-3,5-methano-2H-cyclopenta[b]furan-6-yl-oxycarbonyl)dif-
luoromethanesulfonate, and
4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate.
[0111] Of these, preferred photoacid generators are sulfonium
salts, bissulfonyldiazomethanes, N-sulfonyloxyimides,
oxime-O-sulfonates and glyoxime derivatives. More preferred
photoacid generators are sulfonium salts, bissulfonyldiazomethanes,
N-sulfonyloxyimides, and oxime-O-sulfonates. Typical examples
include triphenylsulfonium p-toluenesulfonate, triphenylsulfonium
camphorsulfonate, triphenylsulfonium pentafluorobenzenesulfonate,
triphenylsulfonium nonafluorobutanesulfonate, triphenylsulfonium
4-(4'-toluenesulfonyloxy)benzenesulfonate, triphenylsulfonium
2,4,6-triisopropylbenzenesulfonate,
4-tert-butoxyphenyldiphenylsulfonium p-toluenesulfonate,
4-tert-butoxyphenyldiphenylsulfonium camphorsulfonate,
4-tert-butoxyphenyldiphenylsulfonium
4-(4'-toluenesulfonyl-oxy)benzenesulfonate,
tris(4-methylphenyl)sulfonium camphorsulfonate,
tris(4-tert-butylphenyl)sulfonium camphorsulfonate,
4-tert-butylphenyldiphenylsulfonium camphorsulfonate,
4-tert-butylphenyldiphenylsulfonium nonafluoro-1-butane-sulfonate,
4-tert-butylphenyldiphenylsulfonium
pentafluoroethyl-perfluorocyclohexanesulfonate,
4-tert-butylphenyldiphenylsulfonium perfluoro-1-octane-sulfonate,
triphenylsulfonium 1,1-difluoro-2-naphthylethanesulfonate,
triphenylsulfonium
1,1,2,2-tetrafluoro-2-(norbornan-2-yl)-ethanesulfonate,
triphenylsulfonium
2-benzoyloxy-1,1,3,3,3-pentafluoro-propanesulfonate,
triphenylsulfonium
1,1,3,3,3-pentafluoro-2-(pivaloyloxy)-propanesulfonate,
triphenylsulfonium
2-cyclohexanecarbonyloxy-1,1,3,3,3-penta-fluoropropanesulfonate,
triphenylsulfonium
2-(2-naphthoyloxy)-1,1,3,3,3-pentafluoro-propanesulfonate,
triphenylsulfonium
adamantanemethoxycarbonyldifluoromethane-sulfonate,
triphenylsulfonium
1-(3-hydroxymethyladamantane)methoxy-carbonyldifluoromethanesulfonate,
triphenylsulfonium methoxycarbonyldifluoromethanesulfonate,
4-tert-butylphenyldiphenylsulfonium
2-benzoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
4-tert-butylphenyldiphenylsulfonium
1,1,3,3,3-pentafluoro-2-(pivaloyloxy)propanesulfonate,
4-tert-butylphenyldiphenylsulfonium
2-cyclohexanecarbonyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
4-tert-butylphenyldiphenylsulfonium
2-(2-naphthoyloxy)-1,1,3,3,3-pentafluoropropanesulfonate,
4-tert-butylphenyldiphenylsulfonium
adamantanemethoxy-carbonyldifluoromethanesulfonate,
4-tert-butylphenyldiphenylsulfonium
1-(3-hydroxymethyl-adamantane)methoxycarbonyldifluoromethanesulfonate,
4-tert-butylphenyldiphenylsulfonium
methoxycarbonyldifluoro-methanesulfonate,
2-oxo-2-phenylethylthiacyclopentanium
2-benzoyloxy-1,1,3,3,3-pentafluoropropanesulfonate,
2-oxo-2-phenylethylthiacyclopentanium
2-cyclohexanecarbonyl-oxy-1,1,3,3,3-pentafluoropropanesulfonate,
triphenylsulfonium perfluoro-1,3-propylenebissulfonylimide,
triphenylsulfonium bispentafluoroethylsulfonylimide,
bis(tert-butylsulfonyl)diazomethane,
bis(cyclohexylsulfonyl)diazomethane,
bis(2,4-dimethylphenylsulfonyl)diazomethane,
bis(4-(n-hexyloxy)phenylsulfonyl)diazomethane,
bis(2-methyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,
bis(2,5-dimethyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,
bis(3,5-dimethyl-4-(n-hexyloxy)phenylsulfonyl)diazomethane,
bis(2-methyl-5-isopropyl-4-(n-hexyloxy)phenylsulfonyl)-diazomethane,
bis(4-tert-butylphenylsulfonyl)diazomethane,
N-camphorsulfonyloxy-5-norbornene-2,3-dicarboxylic acid imide,
N-p-toluenesulfonyloxy-5-norbornene-2,3-dicarboxylic acid imide,
2-[2,2,3,3,4,4,5,5-octafluoro-1-(nonafluorobutylsulfonyloxy-imino)-pentyl-
]-fluorene,
2-[2,2,3,3,4,4-pentafluoro-1-(nonafluorobutylsulfonyloxy-imino)-butyl]-fl-
uorene,
2-[2,2,3,3,4,4,5,5,6,6-decafluoro-1-(nonafluorobutylsulfonyl-oxyim-
ino)-hexyl]-fluorene,
2-[2,2,3,3,4,4,5,5-octafluoro-1-(2-(cyclohexanecarbonyloxy)-1,1,3,3,3-pen-
tafluoropropanesulfonyloxyimino)-pentyl]-fluorene,
2-[2,2,3,3,4,4-pentafluoro-1-(2-(cyclohexanecarbonyloxy)-1,1,3,3,3-pentaf-
luoropropanesulfonyloxyimino)-butyl]-fluorene, and
2-[2,2,3,3,4,4,5,5,6,6-decafluoro-1-(nonafluorobutyl-sulfonyloxyimino)-he-
xyl]-fluorene.
[0112] In the resist composition, an appropriate amount of the
photoacid generator is, but not limited to, 0.1 to 10 parts, and
especially 0.1 to 5 parts by weight per 100 parts by weight of the
base resin. Too high a proportion of the photoacid generator may
give rise to problems of degraded resolution and foreign matter
upon development and resist film peeling. The photoacid generators
may be used alone or in admixture of two or more. The transmittance
of the resist film can be controlled by using a photoacid generator
having a low transmittance at the exposure wavelength and adjusting
the amount of the photoacid generator added.
[0113] It is noted that an acid diffusion controlling function may
be provided when two or more photoacid generators are used in
admixture provided that one photoacid generator is an onium salt
capable of generating a weak acid. Specifically, in a system using
a mixture of a photoacid generator capable of generating a strong
acid (e.g., fluorinated sulfonic acid) and an onium salt capable of
generating a weak acid (e.g., non-fluorinated sulfonic acid), if
the strong acid generated from the photoacid generator upon
exposure to high-energy radiation collides with the unreacted onium
salt having a weak acid anion, then a salt exchange occurs whereby
the weak acid is released and an onium salt having a strong acid
anion is formed. In this course, the strong acid is exchanged into
the weak acid having a low catalysis, incurring apparent
deactivation of the acid for enabling to control acid
diffusion.
[0114] If an onium salt capable of generating a strong acid and an
onium salt capable of generating a weak acid are used in admixture,
an exchange from the strong acid to the weak acid as above can take
place, but it never happens that the weak acid collides with the
unreacted onium salt capable of generating a strong acid to induce
a salt exchange. This is because of a likelihood of an onium cation
forming an ion pair with a stronger acid anion.
[0115] In the resist composition, there may be added a compound
which is decomposed with an acid to generate another acid, that is,
acid-amplifier compound. For these compounds, reference should be
made to J. Photopolym. Sci. and Tech., 8, 43-44, 45-46 (1995), and
ibid., 9, 29-30 (1996).
[0116] Examples of the acid-amplifier compound include
tert-butyl-2-methyl-2-tosyloxymethyl acetoacetate and
2-phenyl-2-(2-tosyloxyethyl)-1,3-dioxolane, but are not limited
thereto. Of well-known photoacid generators, many of those
compounds having poor stability, especially poor thermal stability
exhibit an acid amplifier-like behavior.
[0117] In the resist composition, an appropriate amount of the
acid-amplifier compound is up to 2 parts, and especially up to 1
part by weight per 100 parts by weight of the base resin. Excessive
amounts of the acid-amplifier compound make diffusion control
difficult, leading to degradation of resolution and pattern
profile.
Organic Solvent
[0118] The organic solvent used herein may be any organic solvent
in which the base resin, acid generator, and additives are soluble.
Illustrative, non-limiting, examples of the organic solvent include
ketones such as cyclohexanone and methyl amyl ketone; alcohols such
as 3-methoxybutanol, 3-methyl-3-methoxybutanol,
1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ethers such as
propylene glycol monomethyl ether, ethylene glycol monomethyl
ether, propylene glycol monoethyl ether, ethylene glycol monoethyl
ether, propylene glycol dimethyl ether, and diethylene glycol
dimethyl ether; esters such as propylene glycol monomethyl ether
acetate (PGMEA), propylene glycol monoethyl ether acetate, ethyl
lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate,
ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl
propionate, and propylene glycol mono-tert-butyl ether acetate; and
lactones such as .gamma.-butyrolactone. These solvents may be used
alone or in combinations of two or more thereof. Of the above
organic solvents, it is recommended to use diethylene glycol
dimethyl ether, 1-ethoxy-2-propanol, propylene glycol monomethyl
ether acetate, and mixtures thereof because the acid generator is
most soluble therein.
[0119] An appropriate amount of the organic solvent used is about
200 to 1,000 parts, especially about 400 to 800 parts by weight per
100 parts by weight of the base resin in the resist
composition.
Nitrogen-Containing Compound
[0120] In the resist composition, an organic nitrogen-containing
compound or compounds may be compounded as a sensitivity regulator.
The organic nitrogen-containing compound used herein is preferably
a compound capable of suppressing the rate of diffusion when the
acid generated by the photoacid generator diffuses within the
resist film. The inclusion of organic nitrogen-containing compound
holds down the rate of acid diffusion within the resist film,
resulting in better resolution. In addition, it suppresses changes
in sensitivity following exposure and reduces substrate and
environment dependence, as well as improving the exposure latitude
and the pattern profile.
[0121] The organic nitrogen-containing compound used herein may be
any of well-known organic nitrogen-containing compounds which are
commonly used in prior art resist compositions, especially
chemically amplified resist compositions. Suitable organic
nitrogen-containing compounds include primary, secondary, and
tertiary aliphatic amines, mixed amines, aromatic amines,
heterocyclic amines, nitrogen-containing compounds having carboxyl
group, nitrogen-containing compounds having sulfonyl group,
nitrogen-containing compounds having hydroxyl group,
nitrogen-containing compounds having hydroxyphenyl group, alcoholic
nitrogen-containing compounds, amide derivatives, imide
derivatives, and carbamate derivatives.
[0122] Examples of suitable primary aliphatic amines include
ammonia, methylamine, ethylamine, n-propylamine, isopropylamine,
n-butylamine, isobutylamine, sec-butylamine, tert-butylamine,
pentylamine, tert-amylamine, cyclopentylamine, hexylamine,
cyclohexylamine, heptylamine, octylamine, nonylamine, decylamine,
dodecylamine, cetylamine, methylenediamine, ethylenediamine, and
tetraethylenepentamine. Examples of suitable secondary aliphatic
amines include dimethylamine, diethylamine, di-n-propylamine,
diisopropylamine, di-n-butylamine, diisobutylamine,
di-sec-butylamine, dipentylamine, dicyclopentylamine, dihexylamine,
dicyclohexylamine, diheptylamine, dioctylamine, dinonylamine,
didecylamine, didodecylamine, dicetylamine,
N,N-dimethylmethylenediamine, N,N-dimethylethylenediamine, and
N,N-dimethyltetraethylenepentamine. Examples of suitable tertiary
aliphatic amines include trimethylamine, triethylamine,
tri-n-propylamine, triisopropylamine, tri-n-butylamine,
triisobutylamine, tri-sec-butylamine, tripentylamine,
tricyclopentylamine, trihexylamine, tricyclohexylamine,
triheptylamine, trioctylamine, trinonylamine, tridecylamine,
tridodecylamine, tricetylamine,
N,N,N',N'-tetramethylmethylenediamine,
N,N,N',N'-tetramethylethylenediamine, and
N,N,N',N'-tetramethyltetraethylenepentamine.
[0123] Examples of suitable mixed amines include
dimethylethylamine, methylethylpropylamine, benzylamine,
phenethylamine, and benzyldimethylamine. Examples of suitable
aromatic and heterocyclic amines include aniline derivatives (e.g.,
aniline, N-methylaniline, N-ethylaniline, N-propylaniline,
N,N-dimethylaniline, 2-methylaniline, 3-methylaniline,
4-methylaniline, ethylaniline, propylaniline, trimethylaniline,
2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 2,4-dinitroaniline,
2,6-dinitroaniline, 3,5-dinitroaniline, and N,N-dimethyltoluidine),
diphenyl(p-tolyl)amine, methyldiphenylamine, triphenylamine,
phenylenediamine, naphthylamine, diaminonaphthalene, pyrrole
derivatives (e.g., pyrrole, 2H-pyrrole, 1-methylpyrrole,
2,4-dimethylpyrrole, 2,5-dimethylpyrrole, and N-methylpyrrole),
oxazole derivatives (e.g., oxazole and isooxazole), thiazole
derivatives (e.g., thiazole and isothiazole), imidazole derivatives
(e.g., imidazole, 4-methylimidazole, and
4-methyl-2-phenylimidazole), pyrazole derivatives, furazan
derivatives, pyrroline derivatives (e.g., pyrroline and
2-methyl-1-pyrroline), pyrrolidine derivatives (e.g., pyrrolidine,
N-methylpyrrolidine, pyrrolidinone, and N-methylpyrrolidone),
imidazoline derivatives, imidazolidine derivatives, pyridine
derivatives (e.g., pyridine, methylpyridine, ethylpyridine,
propylpyridine, butylpyridine, 4-(1-butylpentyl)pyridine,
dimethylpyridine, trimethylpyridine, triethylpyridine,
phenylpyridine, 3-methyl-2-phenylpyridine, 4-tert-butylpyridine,
diphenylpyridine, benzylpyridine, methoxypyridine, butoxypyridine,
dimethoxypyridine, 4-pyrrolidinopyridine,
2-(1-ethylpropyl)pyridine, aminopyridine, and
dimethylaminopyridine), pyridazine derivatives, pyrimidine
derivatives, pyrazine derivatives, pyrazoline derivatives,
pyrazolidine derivatives, piperidine derivatives, piperazine
derivatives, morpholine derivatives, indole derivatives, isoindole
derivatives, 1H-indazole derivatives, indoline derivatives,
quinoline derivatives (e.g., quinoline and
3-quinolinecarbonitrile), isoquinoline derivatives, cinnoline
derivatives, quinazoline derivatives, quinoxaline derivatives,
phthalazine derivatives, purine derivatives, pteridine derivatives,
carbazole derivatives, phenanthridine derivatives, acridine
derivatives, phenazine derivatives, 1,10-phenanthroline
derivatives, adenine derivatives, adenosine derivatives, guanine
derivatives, guanosine derivatives, uracil derivatives, and uridine
derivatives.
[0124] Examples of suitable nitrogen-containing compounds having
carboxyl group include aminobenzoic acid, indolecarboxylic acid,
and amino acid derivatives (e.g. nicotinic acid, alanine, alginine,
aspartic acid, glutamic acid, glycine, histidine, isoleucine,
glycylleucine, leucine, methionine, phenylalanine, threonine,
lysine, 3-aminopyrazine-2-carboxylic acid, and methoxyalanine).
Examples of suitable nitrogen-containing compounds having sulfonyl
group include 3-pyridinesulfonic acid and pyridinium
p-toluenesulfonate. Examples of suitable nitrogen-containing
compounds having hydroxyl group, nitrogen-containing compounds
having hydroxyphenyl group, and alcoholic nitrogen-containing
compounds include 2-hydroxypyridine, aminocresol,
2,4-quinolinediol, 3-indolemethanol hydrate, monoethanolamine,
diethanolamine, triethanolamine, N-ethyldiethanolamine,
N,N-diethylethanolamine, triisopropanolamine, 2,2'-iminodiethanol,
2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol,
4-(2-hydroxyethyl)morpholine, 2-(2-hydroxyethyl)pyridine,
1-(2-hydroxyethyl)piperazine,
1-[2-(2-hydroxyethoxy)ethyl]piperazine, piperidine ethanol,
1-(2-hydroxyethyl)pyrrolidine, 1-(2-hydroxyethyl)-2-pyrrolidinone,
3-piperidino-1,2-propanediol, 3-pyrrolidino-1,2-propanediol,
8-hydroxyjulolidine, 3-quinuclidinol, 3-tropanol,
1-methyl-2-pyrrolidine ethanol, 1-aziridine ethanol,
N-(2-hydroxyethyl)phthalimide, and
N-(2-hydroxyethyl)isonicotinamide. Examples of suitable amide
derivatives include formamide, N-methylformamide,
N,N-dimethylformamide, acetamide, N-methylacetamide,
N,N-dimethylacetamide, propionamide, benzamide, and
1-cyclohexylpyrrolidone. Suitable imide derivatives include
phthalimide, succinimide, and maleimide. Suitable carbamate
derivatives include N-t-butoxycarbonyl-N,N-dicyclohexylamine,
N-t-butoxycarbonylbenzimidazole and oxazolidinone.
[0125] In addition, organic nitrogen-containing compounds of the
following general formula (B)-1 may also be included alone or in
admixture.
N(X).sub.n(Y).sub.3-n (B)-1
[0126] In the formula, n is equal to 1, 2 or 3; side chain Y is
independently hydrogen or a straight, branched or cyclic
C.sub.1-C.sub.20 alkyl group which may contain an ether or hydroxyl
group; and side chain X is independently selected from groups of
the following general formulas (X)-1 to (X)-3, and two or three X's
may bond together to form a ring.
##STR00045##
[0127] In the formulas, R.sup.300, R.sup.302 and R.sup.305 are
independently straight or branched C.sub.1-C.sub.4 alkylene groups;
R.sup.301 and R.sup.304 are independently hydrogen, or straight,
branched or cyclic C.sub.1-C.sub.20 alkyl groups which may contain
at least one hydroxyl, ether, ester group or lactone ring;
R.sup.303 is a single bond or a straight or branched
C.sub.1-C.sub.4 alkylene group; and R.sup.306 is a straight,
branched or cyclic C.sub.1-C.sub.20 alkyl group which may contain
at least one hydroxyl, ether, ester group or lactone ring.
[0128] Illustrative examples of the compounds of formula (B)-1
include tris(2-methoxymethoxyethyl)amine,
tris{2-(2-methoxyethoxy)ethyl}amine,
tris{2-(2-methoxyethoxymethoxy)ethyl}amine,
tris{2-(1-methoxyethoxy)ethyl}amine,
tris{2-(1-ethoxyethoxy)ethyl}amine,
tris{2-(1-ethoxypropoxy)ethyl}amine,
tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine,
4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane,
4,7,13,18-tetraoxa-1,10-diazabicyclo[8.5.5]eicosane,
1,4,10,13-tetraoxa-7,16-diazabicyclooctadecane,
1-aza-12-crown-4,1-aza-15-crown-5,1-aza-18-crown-6,
tris(2-formyloxyethyl)amine, tris(2-acetoxyethyl)amine,
tris(2-propionyloxyethyl)amine, tris(2-butyryloxyethyl)amine,
tris(2-isobutyryloxyethyl)amine, tris(2-valeryloxyethyl)amine,
tris(2-pivaloyloxyethyl)amine,
N,N-bis(2-acetoxyethyl)-2-(acetoxyacetoxy)ethylamine,
tris(2-methoxycarbonyloxyethyl)amine,
tris(2-tert-butoxycarbonyloxyethyl)amine,
tris[2-(2-oxopropoxy)ethyl]amine,
tris[2-(methoxycarbonylmethyl)oxyethyl]amine,
tris[2-(tert-butoxycarbonylmethyloxy)ethyl]amine,
tris[2-(cyclohexyloxycarbonylmethyloxy)ethyl]amine,
tris(2-methoxycarbonylethyl)amine,
tris(2-ethoxycarbonylethyl)amine,
N,N-bis(2-hydroxyethyl)-2-(methoxycarbonyl)ethylamine,
N,N-bis(2-acetoxyethyl)-2-(methoxycarbonyl)ethylamine,
N,N-bis(2-hydroxyethyl)-2-(ethoxycarbonyl)ethylamine,
N,N-bis(2-acetoxyethyl)-2-(ethoxycarbonyl)ethylamine,
N,N-bis(2-hydroxyethyl)-2-(2-methoxyethoxycarbonyl)ethylamine,
N,N-bis(2-acetoxyethyl)-2-(2-methoxyethoxycarbonyl)ethylamine,
N,N-bis(2-hydroxyethyl)-2-(2-hydroxyethoxycarbonyl)ethylamine,
N,N-bis(2-acetoxyethyl)-2-(2-acetoxyethoxycarbonyl)ethylamine,
N,N-bis(2-hydroxyethyl)-2-[(methoxycarbonyl)methoxycarbonyl]-ethylamine,
N,N-bis(2-acetoxyethyl)-2-[(methoxycarbonyl)methoxycarbonyl]-ethylamine,
N,N-bis(2-hydroxyethyl)-2-(2-oxopropoxycarbonyl)ethylamine,
N,N-bis(2-acetoxyethyl)-2-(2-oxopropoxycarbonyl)ethylamine,
N,N-bis(2-hydroxyethyl)-2-(tetrahydrofurfuryloxycarbonyl)-ethylamine,
N,N-bis(2-acetoxyethyl)-2-(tetrahydrofurfuryloxycarbonyl)-ethylamine,
N,N-bis(2-hydroxyethyl)-2-[(2-oxotetrahydrofuran-3-yl)oxy-carbonyl]ethyla-
mine,
N,N-bis(2-acetoxyethyl)-2-[(2-oxotetrahydrofuran-3-yl)oxy-carbonyl]e-
thylamine,
N,N-bis(2-hydroxyethyl)-2-(4-hydroxybutoxycarbonyl)ethylamine,
N,N-bis(2-formyloxyethyl)-2-(4-formyloxybutoxycarbonyl)-ethylamine,
N,N-bis(2-formyloxyethyl)-2-(2-formyloxyethoxycarbonyl)-ethylamine,
N,N-bis(2-methoxyethyl)-2-(methoxycarbonyl)ethylamine,
N-(2-hydroxyethyl)-bis[2-(methoxycarbonyl)ethyl]amine,
N-(2-acetoxyethyl)-bis[2-(methoxycarbonyl)ethyl]amine,
N-(2-hydroxyethyl)-bis[2-(ethoxycarbonyl)ethyl]amine,
N-(2-acetoxyethyl)-bis[2-(ethoxycarbonyl)ethyl]amine,
N-(3-hydroxy-1-propyl)-bis[2-(methoxycarbonyl)ethyl]amine,
N-(3-acetoxy-1-propyl)-bis[2-(methoxycarbonyl)ethyl]amine,
N-(2-methoxyethyl)-bis[2-(methoxycarbonyl)ethyl]amine,
N-butyl-bis[2-(methoxycarbonyl)ethyl]amine,
N-butyl-bis[2-(2-methoxyethoxycarbonyl)ethyl]amine,
N-methyl-bis(2-acetoxyethyl)amine,
N-ethyl-bis(2-acetoxyethyl)amine,
N-methyl-bis(2-pivaloyloxyethyl)amine,
N-ethyl-bis[2-(methoxycarbonyloxy)ethyl]amine,
N-ethyl-bis[2-(tert-butoxycarbonyloxy)ethyl]amine,
tris(methoxycarbonylmethyl)amine, tris(ethoxycarbonylmethyl)amine,
N-butyl-bis(methoxycarbonylmethyl)amine,
N-hexyl-bis(methoxycarbonylmethyl)amine, and
.beta.-(diethylamino)-.delta.-valerolactone.
[0129] Also useful are one or more organic nitrogen-containing
compounds having cyclic structure represented by the following
general formula (B)-2.
##STR00046##
Herein X is as defined above, and R.sup.307 is a straight or
branched C.sub.2-C.sub.20 alkylene group which may contain one or
more carbonyl, ether, ester or sulfide groups.
[0130] Illustrative examples of the organic nitrogen-containing
compounds having formula (B)-2 include
1-[2-(methoxymethoxy)ethyl]pyrrolidine,
1-[2-(methoxymethoxy)ethyl]piperidine,
4-[2-(methoxymethoxy)ethyl]morpholine,
1-[2-[(2-methoxyethoxy)methoxy]ethyl]pyrrolidine,
1-[2-[(2-methoxyethoxy)methoxy]ethyl]piperidine,
4-[2-[(2-methoxyethoxy)methoxy]ethyl]morpholine,
2-(1-pyrrolidinyl)ethyl acetate, 2-piperidinoethyl acetate,
2-morpholinoethyl acetate, 2-(1-pyrrolidinyl)ethyl formate,
2-piperidinoethyl propionate, 2-morpholinoethyl acetoxyacetate,
2-(1-pyrrolidinyl)ethyl methoxyacetate,
4-[2-(methoxycarbonyloxy)ethyl]morpholine,
1-[2-(t-butoxycarbonyloxy)ethyl]piperidine,
4-[2-(2-methoxyethoxycarbonyloxy)ethyl]morpholine, methyl
3-(1-pyrrolidinyl)propionate, methyl 3-piperidinopropionate, methyl
3-morpholinopropionate, methyl 3-(thiomorpholino)propionate, methyl
2-methyl-3-(1-pyrrolidinyl)propionate, ethyl
3-morpholinopropionate, methoxycarbonylmethyl
3-piperidinopropionate, 2-hydroxyethyl
3-(1-pyrrolidinyl)propionate, 2-acetoxyethyl
3-morpholinopropionate, 2-oxotetrahydrofuran-3-yl
3-(1-pyrrolidinyl)propionate, tetrahydrofurfuryl
3-morpholinopropionate, glycidyl 3-piperidinopropionate,
2-methoxyethyl 3-morpholinopropionate, 2-(2-methoxyethoxy)ethyl
3-(1-pyrrolidinyl)propionate, butyl 3-morpholinopropionate,
cyclohexyl 3-piperidinopropionate,
.alpha.-(1-pyrrolidinyl)methyl-.gamma.-butyrolactone,
.beta.-piperidino-.gamma.-butyrolactone,
.beta.-morpholino-.delta.-valerolactone, methyl
1-pyrrolidinylacetate, methyl piperidinoacetate, methyl
morpholinoacetate, methyl thiomorpholinoacetate, ethyl
1-pyrrolidinylacetate, 2-methoxyethyl morpholinoacetate,
2-morpholinoethyl 2-methoxyacetate, 2-morpholinoethyl
2-(2-methoxyethoxy)acetate, 2-morpholinoethyl
2-[2-(2-methoxyethoxy)ethoxy]acetate, 2-morpholinoethyl hexanoate,
2-morpholinoethyl octanoate, 2-morpholinoethyl decanoate,
2-morpholinoethyl laurate, 2-morpholinoethyl myristate,
2-morpholinoethyl palmitate, and 2-morpholinoethyl stearate.
[0131] Also, one or more organic nitrogen-containing compounds
having cyano group represented by the following general formulae
(B)-3 to (B)-6 may be blended.
##STR00047##
Herein, X, R.sup.307 and n are as defined above, and R.sup.308 and
R.sup.309 are each independently a straight or branched
C.sub.1-C.sub.4 alkylene group.
[0132] Illustrative examples of the organic nitrogen-containing
compounds having cyano represented by formulae (B)-3 to (B)-6
include 3-(diethylamino)propiononitrile,
N,N-bis(2-hydroxyethyl)-3-aminopropiononitrile,
N,N-bis(2-acetoxyethyl)-3-aminopropiononitrile,
N,N-bis(2-formyloxyethyl)-3-aminopropiononitrile,
N,N-bis(2-methoxyethyl)-3-aminopropiononitrile,
N,N-bis[2-(methoxymethoxy)ethyl]-3-aminopropiononitrile, methyl
N-(2-cyanoethyl)-N-(2-methoxyethyl)-3-aminopropionate, methyl
N-(2-cyanoethyl)-N-(2-hydroxyethyl)-3-aminopropionate, methyl
N-(2-acetoxyethyl)-N-(2-cyanoethyl)-3-aminopropionate,
N-(2-cyanoethyl)-N-ethyl-3-aminopropiononitrile,
N-(2-cyanoethyl)-N-(2-hydroxyethyl)-3-aminopropiononitrile,
N-(2-acetoxyethyl)-N-(2-cyanoethyl)-3-aminopropiononitrile,
N-(2-cyanoethyl)-N-(2-formyloxyethyl)-3-aminopropiononitrile,
N-(2-cyanoethyl)-N-(2-methoxyethyl)-3-aminopropiononitrile,
N-(2-cyanoethyl)-N-[2-(methoxymethoxy)ethyl]-3-aminopropiono-nitrile,
N-(2-cyanoethyl)-N-(3-hydroxy-1-propyl)-3-aminopropiononitrile,
N-(3-acetoxy-1-propyl)-N-(2-cyanoethyl)-3-aminopropiononitrile,
N-(2-cyanoethyl)-N-(3-formyloxy-1-propyl)-3-aminopropiono-nitrile,
N-(2-cyanoethyl)-N-tetrahydrofurfuryl-3-aminopropiononitrile,
N,N-bis(2-cyanoethyl)-3-aminopropiononitrile,
diethylaminoacetonitrile, N,N-bis(2-hydroxyethyl)aminoacetonitrile,
N,N-bis(2-acetoxyethyl)aminoacetonitrile,
N,N-bis(2-formyloxyethyl)aminoacetonitrile,
N,N-bis(2-methoxyethyl)aminoacetonitrile,
N,N-bis[2-(methoxymethoxy)ethyl]aminoacetonitrile, methyl
N-cyanomethyl-N-(2-methoxyethyl)-3-aminopropionate, methyl
N-cyanomethyl-N-(2-hydroxyethyl)-3-aminopropionate, methyl
N-(2-acetoxyethyl)-N-cyanomethyl-3-aminopropionate,
N-cyanomethyl-N-(2-hydroxyethyl)aminoacetonitrile,
N-(2-acetoxyethyl)-N-(cyanomethyl)aminoacetonitrile,
N-cyanomethyl-N-(2-formyloxyethyl)aminoacetonitrile,
N-cyanomethyl-N-(2-methoxyethyl)aminoacetonitrile,
N-cyanomethyl-N-[2-(methoxymethoxy)ethyl)aminoacetonitrile,
N-cyanomethyl-N-(3-hydroxy-1-propyl)aminoacetonitrile,
N-(3-acetoxy-1-propyl)-N-(cyanomethyl)aminoacetonitrile,
N-cyanomethyl-N-(3-formyloxy-1-propyl)aminoacetonitrile,
N,N-bis(cyanomethyl)aminoacetonitrile,
1-pyrrolidinepropiononitrile, 1-piperidinepropiononitrile,
4-morpholinepropiononitrile, 1-pyrrolidineacetonitrile,
1-piperidineacetonitrile, 4-morpholineacetonitrile, cyanomethyl
3-diethylaminopropionate, cyanomethyl
N,N-bis(2-hydroxyethyl)-3-aminopropionate, cyanomethyl
N,N-bis(2-acetoxyethyl)-3-aminopropionate, cyanomethyl
N,N-bis(2-formyloxyethyl)-3-aminopropionate, cyanomethyl
N,N-bis(2-methoxyethyl)-3-aminopropionate, cyanomethyl
N,N-bis[2-(methoxymethoxy)ethyl]-3-aminopropionate, 2-cyanoethyl
3-diethylaminopropionate, 2-cyanoethyl
N,N-bis(2-hydroxyethyl)-3-aminopropionate, 2-cyanoethyl
N,N-bis(2-acetoxyethyl)-3-aminopropionate, 2-cyanoethyl
N,N-bis(2-formyloxyethyl)-3-aminopropionate, 2-cyanoethyl
N,N-bis(2-methoxyethyl)-3-aminopropionate, 2-cyanoethyl
N,N-bis[2-(methoxymethoxy)ethyl]-3-amino-propionate, cyanomethyl
1-pyrrolidinepropionate, cyanomethyl 1-piperidinepropionate,
cyanomethyl 4-morpholinepropionate, 2-cyanoethyl
1-pyrrolidinepropionate, 2-cyanoethyl 1-piperidinepropionate, and
2-cyanoethyl 4-morpholinepropionate.
[0133] Also included are organic nitrogen-containing compounds
having an imidazole structure and a polar functional group,
represented by the general formula (B)-7.
##STR00048##
Herein, R.sup.310 is a straight, branched or cyclic
C.sub.2-C.sub.20 alkyl group bearing at least one polar functional
group selected from among hydroxyl, carbonyl, ester, ether,
sulfide, carbonate, cyano and acetal groups; R.sup.311, R.sup.312
and R.sup.313 are each independently a hydrogen atom, a straight,
branched or cyclic C.sub.1-C.sub.10 alkyl group, aryl group or
aralkyl group.
[0134] Also included are organic nitrogen-containing compounds
having a benzimidazole structure and a polar functional group,
represented by the general formula (B)-8.
##STR00049##
Herein, R.sup.314 is a hydrogen atom, a straight, branched or
cyclic C.sub.1-C.sub.10 alkyl group, aryl group or aralkyl group.
R.sup.315 is a polar functional group bearing, straight, branched
or cyclic C.sub.1-C.sub.20 alkyl group, and the alkyl group
contains as the polar functional group at least one group selected
from among ester, acetal and cyano groups, and may additionally
contain at least one group selected from among hydroxyl, carbonyl,
ether, sulfide and carbonate groups.
[0135] Further included are heterocyclic nitrogen-containing
compounds having a polar functional group, represented by the
general formulae (B)-9 and (B)-10.
##STR00050##
Herein, A is a nitrogen atom or .ident.C--R.sup.322, B is a
nitrogen atom or .ident.C--R.sup.323, R.sup.316 is a straight,
branched or cyclic C.sub.2-C.sub.20 alkyl group bearing at least
one polar functional group selected from among hydroxyl, carbonyl,
ester, ether, sulfide, carbonate, cyano and acetal groups;
R.sup.317, R.sup.318, R.sup.319 and R.sup.320 are each
independently a hydrogen atom, a straight, branched or cyclic
C.sub.1-C.sub.10 alkyl group or aryl group, or a pair of R.sup.317
and R.sup.318 and a pair of R.sup.319 and R.sup.320, taken
together, may form a benzene, naphthalene or pyridine ring;
R.sup.321 is a hydrogen atom, a straight, branched or cyclic
C.sub.1-C.sub.10 alkyl group or aryl group; R.sup.322 and R.sup.323
each are a hydrogen atom, a straight, branched or cyclic
C.sub.1-C.sub.10 alkyl group or aryl group, or a pair of R.sup.321
and R.sup.323, taken together, may form a benzene or naphthalene
ring.
[0136] Also included are organic nitrogen-containing compounds of
aromatic carboxylic ester structure having the general formulae
(B)-11 to (B)-14.
##STR00051##
Herein R.sup.324 is a C.sub.6-C.sub.20 aryl group or
C.sub.4-C.sub.20 hetero-aromatic group, in which some or all of
hydrogen atoms may be replaced by halogen atoms, straight, branched
or cyclic C.sub.1-C.sub.20 alkyl groups, C.sub.6-C.sub.20 aryl
groups, C.sub.7-C.sub.20 aralkyl groups, C.sub.1-C.sub.10 alkoxy
groups, C.sub.1-C.sub.10 acyloxy groups or C.sub.1-C.sub.10
alkylthio groups. R.sup.325 is CO.sub.2R.sup.326, OR.sup.327 or
cyano group. R.sup.326 is a C.sub.1-C.sub.10 alkyl group, in which
some methylene groups may be replaced by oxygen atoms. R.sup.327 is
a C.sub.1-C.sub.10 alkyl or acyl group, in which some methylene
groups may be replaced by oxygen atoms. R.sup.328 is a single bond,
methylene, ethylene, sulfur atom or
--O(CH.sub.2CH.sub.2O).sub.n-group wherein n is 0, 1, 2, 3 or 4.
R.sup.329 is hydrogen, methyl, ethyl or phenyl. X is a nitrogen
atom or CR.sup.330. Y is a nitrogen atom or CR.sup.331. Z is a
nitrogen atom or CR.sup.332. R.sup.330, R.sup.331 and R.sup.332 are
each independently hydrogen, methyl or phenyl. Alternatively, a
pair of R.sup.330 and R.sup.331 or a pair of R.sup.331 and
R.sup.332 may bond together to form a C.sub.6-C.sub.20 aromatic
ring or C.sub.2-C.sub.20 hetero-aromatic ring.
[0137] Further included are organic nitrogen-containing compounds
of 7-oxanorbornane-2-carboxylic ester structure having the general
formula (B)-15.
##STR00052##
Herein R.sup.333 is hydrogen or a straight, branched or cyclic
C.sub.1-C.sub.10 alkyl group. R.sup.334 and R.sup.335 are each
independently a C.sub.1-C.sub.20 alkyl group, C.sub.6-C.sub.20 aryl
group or C.sub.1-C.sub.20 aralkyl group, which may contain one or
more polar functional groups selected from among ether, carbonyl,
ester, alcohol, sulfide, nitrile, amine, imine, and amide and in
which some hydrogen atoms may be replaced by halogen atoms.
R.sup.334 and R.sup.335, taken together, may form a heterocyclic or
hetero-aromatic ring of 2 to 20 carbon atoms.
[0138] The organic nitrogen-containing compounds may be used alone
or in admixture of two or more. The organic nitrogen-containing
compound is preferably formulated in an amount of 0.001 to 2 parts,
and especially 0.01 to 1 part by weight, per 100 parts by weight of
the base resin. Less than 0.001 part of the nitrogen-containing
compound achieves no or little addition effect whereas more than 2
parts would result in too low a sensitivity.
Other Components
[0139] The resist composition of the invention may include optional
ingredients, for example, a surfactant which is commonly used for
improving the coating characteristics. Optional ingredients may be
added in conventional amounts so long as this does not compromise
the objects of the invention.
[0140] Nonionic surfactants are preferred, examples of which
include perfluoroalkylpolyoxyethylene ethanols, fluorinated alkyl
esters, perfluoroalkylamine oxides, perfluoroalkyl EO-addition
products, and fluorinated organosiloxane compounds. Useful
surfactants are commercially available under the trade names
Fluorad FC-430 and FC-431 from Sumitomo 3M, Ltd., Surflon S-141,
S-145, KH-10, KH-20, KH-30 and KH-40 from Asahi Glass Co., Ltd.,
Unidyne DS-401, DS-403 and DS-451 from Daikin Industry Co., Ltd.,
Megaface F-8151 from Dai-Nippon Ink & Chemicals, Inc., and
X-70-092 and X-70-093 from Shin-Etsu Chemical Co., Ltd. Preferred
surfactants are Fluorad FC-430 from Sumitomo 3M, Ltd., KH-20 and
KH-30 from Asahi Glass Co., Ltd., and X-70-093 from Shin-Etsu
Chemical Co., Ltd.
[0141] To the resist composition of the invention, other components
such as dissolution regulators, carboxylic acid compounds and
acetylene alcohol derivatives may be added if necessary. Optional
components may be added in conventional amounts so long as this
does not compromise the objects of the invention.
[0142] The dissolution regulator which can be added to the resist
composition is a compound having on the molecule at least two
phenolic hydroxyl groups, in which an average of from 0 to 100 mol
% of all the hydrogen atoms on the phenolic hydroxyl groups are
replaced by acid labile groups or a compound having on the molecule
at least one carboxyl group, in which an average of 50 to 100 mol %
of all the hydrogen atoms on the carboxyl groups are replaced by
acid labile groups, both the compounds having an average molecular
weight within a range of 100 to 1,000, and preferably 150 to
800.
[0143] The degree of substitution of the hydrogen atoms on the
phenolic hydroxyl groups with acid labile groups is on average at
least 0 mol %, and preferably at least 30 mol %, of all the
phenolic hydroxyl groups. The upper limit is 100 mol %, and
preferably 80 mol %. The degree of substitution of the hydrogen
atoms on the carboxyl groups with acid labile groups is on average
at least 50 mol %, and preferably at least 70 mol %, of all the
carboxyl groups, with the upper limit being 100 mol %.
[0144] Preferable examples of such compounds having two or more
phenolic hydroxyl groups or compounds having a carboxyl group
include those of formulas (D1) to (D14) below.
##STR00053## ##STR00054##
[0145] In these formulas, R.sup.201 and R.sup.202 are each hydrogen
or a straight or branched C.sub.1-C.sub.8 alkyl or alkenyl group,
for example, hydrogen, methyl, ethyl, butyl, propyl, ethynyl and
cyclohexyl.
[0146] R.sup.203 is hydrogen, a straight or branched
C.sub.1-C.sub.8 alkyl or alkenyl group, or
--(R.sup.207).sub.h--COOH wherein R.sup.207 is a straight or
branched C.sub.1-C.sub.10 alkylene, for example, those exemplified
for R.sup.201 and R.sup.202 and --COOH and --CH.sub.2COOH.
[0147] R.sup.204 is --(CH.sub.2).sub.i-- wherein i=2 to 10,
C.sub.6-C.sub.10 arylene, carbonyl, sulfonyl, an oxygen atom, or a
sulfur atom, for example, ethylene, phenylene, carbonyl, sulfonyl,
oxygen atom or sulfur atom.
[0148] R.sup.205 is a C.sub.1-C.sub.10 alkylene, a C.sub.6-C.sub.10
arylene, carbonyl, sulfonyl, an oxygen atom, or a sulfur atom, for
example, methylene and those exemplified for R.sup.204.
[0149] R.sup.206 is hydrogen, a straight or branched
C.sub.1-C.sub.8 alkyl or alkenyl, or a phenyl or naphthyl group in
which at least one hydrogen atom is substituted by a hydroxyl
group, for example, hydrogen, methyl, ethyl, butyl, propyl,
ethynyl, cyclohexyl, hydroxyl-substituted phenyl, and
hydroxyl-substituted naphthyl.
[0150] R.sup.208 is hydrogen or hydroxyl.
[0151] The letter j is an integer from 0 to 5; u and h are each 0
or 1; s, t, s', t', s'', and t'' are each numbers which satisfy
s+t=8, s'+t'=5, and s''+t''=4, and are such that each phenyl
skeleton has at least one hydroxyl group; and a is a number such
that the compounds of formula (D8) or (D9) have a weight average
molecular weight of from 100 to 1,000.
[0152] Exemplary acid labile groups on the dissolution regulator
include a variety of such groups, typically groups of the general
formulae (L1) to (L4), tertiary C.sub.4-C.sub.20 alkyl groups,
trialkylsilyl groups in which each of the alkyls has 1 to 6 carbon
atoms, and C.sub.4-C.sub.20 oxoalkyl groups. Examples of the
respective groups are as previously described.
[0153] The dissolution regulator may be formulated in an amount of
0 to 50 parts, preferably 0 to 40 parts, and more preferably 0 to
30 parts by weight, per 100 parts by weight of the base resin, and
may be used singly or as a mixture of two or more thereof. The use
of more than 50 parts of the dissolution regulator would lead to
slimming of the patterned film, and thus a decline in
resolution.
[0154] The dissolution regulator can be synthesized by introducing
acid labile groups into a compound having phenolic hydroxyl or
carboxyl groups in accordance with an organic chemical
formulation.
[0155] In the resist composition, a carboxylic acid compound may be
blended. The carboxylic acid compound used herein may be one or
more compounds selected from Groups I and II below, but is not
limited thereto. Including this compound improves the PED stability
of the resist and ameliorates edge roughness on nitride film
substrates.
Group I:
[0156] Compounds in which some or all of the hydrogen atoms on the
phenolic hydroxyl groups of the compounds of general formulas (A1)
to (A10) below are replaced by --R.sup.401--COOH (wherein R.sup.401
is a straight or branched C.sub.1-C.sub.10 alkylene group), and in
which the molar ratio C/(C+D) of phenolic hydroxyl groups (C) to
.ident.C--COOH groups (D) in the molecule is from 0.1 to 1.0.
##STR00055## ##STR00056##
[0157] In these formulas, R.sup.402 and R.sup.403 are each hydrogen
or a straight or branched C.sub.1-C.sub.8 alkyl or alkenyl;
R.sup.404 is hydrogen, a straight or branched C.sub.1-C.sub.8 alkyl
or alkenyl, or a --(R.sup.409).sub.h--COOR' group (R' being
hydrogen or --R.sup.409--COOH); R.sup.405 is --(CH.sub.2).sub.i--
(wherein i is 2 to 10), a C.sub.6-C.sub.10 arylene, carbonyl,
sulfonyl, an oxygen atom, or a sulfur atom; R.sup.406 is a
C.sub.1-C.sub.10 alkylene, a C.sub.6-C.sub.10 arylene, carbonyl,
sulfonyl, an oxygen atom, or a sulfur atom; R.sup.407 is hydrogen,
a straight or branched C.sub.1-C.sub.8 alkyl or alkenyl, or a
hydroxyl-substituted phenyl or naphthyl; R.sup.408 is hydrogen or
methyl; R.sup.409 is a straight or branched C.sub.1-C.sub.10
alkylene; R.sup.410 is hydrogen, a straight or branched
C.sub.1-C.sub.8 alkyl or alkenyl, or a --R.sup.411--COOH group;
R.sup.411 is a straight or branched C.sub.1-C.sub.10 alkylene; the
letter j is a number from 0 to 3; u is a number from 1 to 4; h is a
number from 0 to 4; s1, t1, s2, t2, s3, t3, s4, and t4 are each
numbers which satisfy s1+t1=8, s2+t2=5, s3+t3=4, and s4+t4=6, and
are such that each phenyl structure has at least one hydroxyl
group; .kappa. is a number such that the compound of formula (A6)
may have a weight average molecular weight of 1,000 to 5,000; and
.lamda. is a number such that the compound of formula (A7) may have
a weight average molecular weight of 1,000 to 10,000.
Group II:
[0158] Compounds of general formulas (A11) to (A15) below.
##STR00057##
[0159] In these formulas, R.sup.402, R.sup.403, and R.sup.411 are
as defined above; R.sup.412 is hydrogen or hydroxyl; s5 and t5 are
numbers which satisfy s5.gtoreq.0, t5.gtoreq.0, and s5+t5=5; and h
is a number from 0 to 4.
[0160] Illustrative, non-limiting examples of the compound having a
carboxyl group include compounds of the general formulas AI-1 to
AI-14 and AII-1 to AII-10 below.
##STR00058## ##STR00059## ##STR00060##
In the above formulas, R'' is hydrogen or a --CH.sub.2COOH group
such that the --CH.sub.2COOH group accounts for 10 to 100 mol % of
R'' in each compound, .kappa. and .lamda. are as defined above.
[0161] The compound having a .ident.C--COOH group may be used
singly or as combinations of two or more thereof. The compound
having a .ident.C--COOH group is added in an amount ranging from 0
to 5 parts, preferably 0.1 to 5 parts, more preferably 0.1 to 3
parts, further preferably 0.1 to 2 parts by weight, per 100 parts
by weight of the base resin. More than 5 parts of the compound can
reduce the resolution of the resist composition.
[0162] Preferred examples of the acetylene alcohol derivative which
can be added to the resist composition include those having the
general formula (S1) or (S2) below.
##STR00061##
In the formulas, R.sup.501, R.sup.502, R.sup.503, R.sup.504, and
R.sup.505 are each hydrogen or a straight, branched or cyclic
C.sub.1-C.sub.8 alkyl; and X and Y are each 0 or a positive number,
satisfying 0.ltoreq.X.ltoreq.30, 0.ltoreq.Y.ltoreq.30, and
0.ltoreq.X+Y.ltoreq.40.
[0163] Preferable examples of the acetylene alcohol derivative
include Surfynol 61, Surfynol 82, Surfynol 104, Surfynol 104E,
Surfynol 104H, Surfynol 104A, Surfynol TG, Surfynol PC, Surfynol
440, Surfynol 465, and Surfynol 485 from Air Products and Chemicals
Inc., and Surfynol E1004 from Nisshin Chemical Industries Ltd.
[0164] The acetylene alcohol derivative is preferably added in an
amount of 0 to 2 parts, more preferably 0.01 to 2 parts, and even
more preferably 0.02 to 1 part by weight per 100 parts by weight of
the base resin in the resist composition. More than 2 parts by
weight would result in a resist having a low resolution.
[0165] Pattern formation using the resist composition of the
invention may be carried out by a known lithographic technique. For
example, the resist composition is applied onto a substrate such as
a silicon wafer by spin coating or the like to form a resist film
having a thickness of 0.05 to 2.0 .mu.m, which is then pre-baked on
a hot plate at 60 to 150.degree. C. for 0.1 to 10 minutes, and
preferably at 80 to 140.degree. C. for 0.5 to 5 minutes. A
patterning mask having the desired pattern is then placed over the
resist film, and the film exposed through the mask to an electron
beam or to high-energy radiation such as deep-UV, excimer laser, or
x-ray in a dose of about 1 to 200 mJ/cm.sup.2, and preferably about
10 to 100 mJ/cm.sup.2. Light exposure may be done by a conventional
exposure process or in some cases, by an immersion process of
providing liquid (typically water) impregnation between the lens
and the resist. The resist film is then post-exposure baked (PEB)
on a hot plate at 60 to 150.degree. C. for 0.1 to 5 minutes, and
preferably at 80 to 140.degree. C. for 0.5 to 3 minutes. Finally,
development is carried out using as the developer an aqueous alkali
solution, such as a 0.1 to 5 wt % (preferably 2 to 3 wt %) aqueous
solution of tetramethylammonium hydroxide (TMAH), this being done
by a conventional method such as dip, puddle or spray development
for a period of 0.1 to 3 minutes, and preferably 0.5 to 2 minutes.
These steps result in the formation of the desired pattern on the
substrate. Of the various types of high-energy radiation that may
be used, the resist composition of the invention is best suited to
fine pattern formation with, in particular, deep-UV rays having a
wavelength of 260 to 120 nm, excimer lasers, x-rays, or electron
beams. The desired pattern may not be obtainable outside the upper
and lower limits of the above range.
EXAMPLE
[0166] Synthesis Examples, Examples and Comparative Examples are
given below by way of illustration and not by way of limitation. Mw
is weight average molecular weight.
Monomer Synthesis Examples
[0167] Ester compounds were synthesized in accordance with the
following formulation.
Monomer Synthesis Example 1
Synthesis of 2-methyl-4-oxatricyclo[5.2.1.0.sup.2,6]decan-3-yl
methacrylate
Monomer Synthesis Example 1-1
Synthesis of 2-methyl-4-oxatricyclo[5.2.1.0.sup.2,6]decan-3-yl
acetate
##STR00062##
[0169] A mixture of 63 g of
2-methyl-4-oxatricyclo[5.2.1.0.sup.2,6]-decan-3-ol, 42 g of
pyridine, and 51 g of acetic anhydride was heated at 50.degree. C.
for 5 hours. The reaction mixture was concentrated. The concentrate
was purified by distillation, obtaining 74 g (yield 96%) of the
target compound.
2-methyl-4-oxatricyclo[5.2.1.0.sup.2,6]decan-3-yl acetate
[0170] Colorless liquid
[0171] Boiling point: 84.degree. C./40 Pa
[0172] GC-MS (EI): (m/z).sup.+=29, 43, 55, 67, 79, 93, 107, 122,
151, 167, 209 [(M-H).sup.+]
[0173] IR (thin film): .nu.=2966, 2879, 1739, 1479, 1463, 1375,
1241, 1222, 1195, 1116, 1083, 1035, 1004, 973, 952, 925, 908
cm.sup.-1
[0174] .sup.1H-NMR (600 MHz in CDCl.sub.3): .delta.=1.03 (3H, s),
1.24-1.36 (3H, m), 1.44 (1H, m), 1.52 (1H, m), 1.70 (1H, m), 2.00
(2H, m), 2.02 (3H, s), 2.20 (1H, m), 3.83 (1H, dd, J=27.1, 9.3 Hz),
3.84 (1H, dd, J=32.6, 9.3 Hz), 6.14 (1H, s) ppm
[0175] .sup.13C-NMR (150 MHz in CDCl.sub.3): .delta.=21.22, 21.51,
21.97, 23.33, 40.35, 41.19, 47.02, 51.70, 54.14, 68.33, 100.6,
170.5 ppm
Monomer Synthesis Example 1-2
Synthesis of 2-methyl-4-oxatricyclo[5.2.1.0.sup.2,6]decan-3-yl
methacrylate
##STR00063##
[0177] A mixture of 73 g of
2-methyl-4-oxatricyclo[5.2.1.0.sup.2,6]-decan-3-yl acetate, 150 g
of methacrylic acid, and 40 mg of
2,2'-methylenebis(6-t-butyl-p-cresol) was heated at 50.degree. C.
under atmospheric pressure for 30 minutes, after which under a
reduced pressure of 0.20 kPa, the reaction mixture was heated for
18 hours for distilling off the acetic acid formed. The reaction
mixture was purified by distillation, obtaining 72 g (yield 91%) of
the target compound.
2-methyl-4-oxatricyclo[5.2.1.0.sup.2,6]decan-3-yl methacrylate
[0178] Colorless liquid
[0179] Boiling point: 91.degree. C./13 Pa
[0180] GC-MS (EI): (m/z).sup.+=29, 41, 55, 67, 79, 93, 107, 121,
133, 151, 167, 235 [(M-H).sup.+]
[0181] IR (thin film): .nu.=2964, 2879, 1722, 1637, 1461, 1380,
1321, 1295, 1170, 1157, 1112, 1079, 1006, 971, 954, 939, 917
cm.sup.-1
[0182] .sup.1H-NMR (600 MHz in CDCl.sub.3): .delta.=1.07 (3H, s),
1.23-1.37 (3H, m), 1.56 (1H, m), 1.47 (1H, m), 1.72 (1H, m), 1.91
(3H, m), 2.03 (2H, m), 2.22 (1H, m), 3.85 (1H, dd, J=28.4, 9.6 Hz),
3.86 (1H, dd, J=33.7, 9.6 Hz), 5.54 (1H, m), 6.08 (1H, m), 6.20
(1H, s) ppm
[0183] .sup.13C-NMR (150 MHz in CDCl.sub.3): .delta.=18.32, 21.85,
22.13, 23.52, 40.50, 41.35, 47.17, 51.97, 54.58, 68.45, 100.9,
125.7, 136.8, 166.7 ppm
Monomer Synthesis Example 2
Synthesis of 4-oxatricyclo[5.2.1.0.sup.2,6]decan-3-yl
methacrylate
##STR00064##
[0185] The target compound,
4-oxatricyclo[5.2.1.0.sup.2,6]decan-3-yl methacrylate was
synthesized by following the same procedure as in Monomer Synthesis
Example 1 aside from using an equimolar amount of
4-oxatricyclo[5.2.1.0.sup.2,6]decan-3-ol instead of
2-methyl-4-oxatricyclo[5.2.1.0.sup.2,6]decan-3-ol.
4-oxatricyclo[5.2.1.0.sup.2,6]decan-3-yl methacrylate
[0186] Colorless liquid
[0187] Boiling point: 81.degree. C./11 Pa
[0188] IR (thin film): .nu.=2956, 2879, 1722, 1637, 1475, 1452,
1403, 1380, 1363, 1326, 1311, 1297, 1267, 1211, 1153, 1116, 1101,
1049, 1020, 1002, 950, 933, 912, 900, 825, 813, 800 cm.sup.-1
[0189] .sup.1H-NMR (600 MHz in CDCl.sub.3): .delta.=1.25-1.40 (2H,
m), 1.43 (1H, m), 1.45-1.55 (3H, m), 1.91 (3H, dd), 2.23 (1H, m),
2.42 (1H, m), 2.55-2.70 (2H, m), 3.89 (1H, dd), 3.97 (1H, dd), 5.54
(1H, dq), 6.06 (1H, dq), 6.20 (1H,s)
[0190] .sup.13C-NMR (150 MHz in CDCl.sub.3): .delta.=18.12, 22.41,
23.55, 39.07, 40.28, 41.99, 43.92, 52.36, 68.79, 100.58, 125.49,
136.57, 166.71
Monomer Synthesis Example 3
Synthesis of 3-methyl-2-oxaspiro[4,5]decan-1-yl methacrylate
Monomer Synthesis Example 3-1
Synthesis of 3-methyl-2-oxaspiro[4,5]decan-1-ol
##STR00065##
[0192] To a mixture of 40 g of ethylmagnesium bromide and 120 g of
tetrahydrofuran was added a mixture of 50 g of
cyclohexylmethylenecyclohexylamine and 50 g of tetrahydrofuran. The
resulting mixture was stirred for 2 hours under tetrahydrofuran
reflux conditions. Thereafter, 21 g of propylene oxide was added
under ice cooling to the reaction mixture, which was stirred for a
further 12 hours at room temperature. Then 30 g of acetic acid was
added to quench the reaction, followed by ordinary aqueous workup,
obtaining 74 g of a crude product,
1-[(1-cyclohexylimino-methyl)cyclohexyl]propan-2-ol. To 74 g of the
crude product were added 16 g of acetic acid, 400 g of hexane, and
280 g of water. The mixture was stirred at 50.degree. C. for 12
hours. The reaction mixture was then subjected to ordinary aqueous
workup and distillation for purification, obtaining 28 g (yield
63%) of the target compound,
3-methyl-2-oxaspiro-[4,5]decan-1-ol.
3-methyl-2-oxaspiro[4,5]decan-1-ol
[0193] colorless liquid
[0194] boiling point: 68.degree. C./27 Pa
[0195] GC-MS (EI): (m/z).sup.+=29, 41, 55, 67, 82, 95, 109, 124,
137, 155, 169 [(M-H).sup.+]
[0196] IR of isomeric mixture (thin film): .nu.=3404, 2966, 2927,
2854, 1450, 1378, 1348, 1309, 1259, 1174, 1149, 1128, 1106, 1078,
1041, 1002, 919, 908, 879, 811 cm.sup.-1
[0197] .sup.1H-NMR (600 MHz in CDCl.sub.3): .delta.=1.28 (3H, d,
J=6.2 Hz), 1.30-1.58 (11H, m), 1.88-1.97 (1H, m), 3.34 (1H, s),
4.20 (1H, m), 4.97 (1H, s) ppm (peak assignment of main
isomers)
[0198] .sup.13C-NMR (150 MHz in CDCl.sub.3): .delta.=21.87, 23.78,
26.39, 32.15, 33.47, 36.74, 42.33, 48.25, 74.88, 103.0 ppm (peak
assignment of main isomers)
Monomer Synthesis Example 3-2
Synthesis of 3-methyl-2-oxaspiro[4,5]decan-1-yl acetate
##STR00066##
[0200] A mixture of 11 g of 3-methyl-2-oxaspiro[4,5]decan-1-ol, 7.7
g of pyridine and 9.2 g of acetic anhydride was heated at
50.degree. C. for 12 hours. The reaction mixture was concentrated.
The concentrate was purified by distillation, obtaining 13 g (yield
96%) of the target compound, 3-methyl-2-oxaspiro[4,5]decan-1-yl
acetate.
3-methyl-2-oxaspiro[4,5]decan-1-yl acetate
[0201] Colorless liquid
[0202] Boiling point: 74.degree. C./17 Pa
[0203] GC-MS (EI): (m/z).sup.+=29, 43, 55, 67, 81, 95, 109, 124,
137, 153, 169, 211 [(M-H).sup.+]
[0204] IR of isomeric mixture (thin film): .nu.=2971, 2931, 2856,
1739, 1452, 1375, 1240, 1132, 1087, 1041, 1008, 989, 954, 927, 898,
881 cm.sup.-1
[0205] .sup.1H-NMR (600 MHz in CDCl.sub.3): .delta.=1.24 (3H, d,
J=6.2 Hz), 1.27-1.53 (11H, m), 1.91-1.94 (1H, m), 2.01 (3H, m),
4.25-4.30 (1H, m), 5.90 (1H, s) ppm (peak assignment of main
isomers)
[0206] .sup.13C-NMR (150 MHz in CDCl.sub.3): .delta.=21.41, 22.58,
23.76, 25.90, 31.86, 33.08, 36.58, 41.77, 47.60, 75.40, 102.7,
170.8 ppm (peak assignment of main isomers)
Monomer Synthesis Example 3-3
Synthesis of 3-methyl-2-oxaspiro[4,5]decan-1-yl methacrylate
##STR00067##
[0208] A mixture of 13 g of 3-methyl-2-oxaspiro[4,5]decan-1-yl
acetate, 24 g of methacrylic acid, and 13 mg of
2,2'-methylenebis(6-t-butyl-p-cresol) was heated at 50.degree. C.
under atmospheric pressure for 30 minutes, after which under a
reduced pressure of 0.20 kPa, the reaction mixture was heated for
18 hours for distilling off the acetic acid formed. The reaction
mixture was purified by distillation, obtaining 11 g (yield 80%) of
the target compound, 3-methyl-2-oxaspiro[4,5]decan-1-yl
methacrylate.
3-methyl-2-oxaspiro[4,5]decan-1-yl methacrylate colorless
liquid
[0209] boiling point: 88.degree. C./13 Pa
[0210] GC-MS (EI): (m/z).sup.+=29, 41, 55, 69, 81, 95, 109, 124,
137, 153, 169, 237 [(M-H).sup.+]
[0211] IR of isomeric mixture (thin film): .nu.=2971, 2929, 2856,
1720, 1637, 1452, 1402, 1378, 1351, 1319, 1295, 1278, 1226, 1164,
1130, 1083, 1052, 1039, 1006, 989, 954, 906, 892, 860, 846, 811
cm.sup.-1
[0212] .sup.1H-NMR (600 MHz in CDCl.sub.3): .delta.=1.26 (3H, d,
J=6.2 Hz), 1.28-1.56 (11H, m), 1.92 (3H, t, J=1.0, 1.4 Hz), 2.05
(1H, m), 4.29-4.37 (1H, m), 5.54 (1H, m), 5.98 (1H, s), 6.07 (1H,
m) ppm (peak assignment of main isomers)
[0213] .sup.13C-NMR (150 MHz in CDCl.sub.3): .delta.=18.34, 22.52,
23.43, 23.63, 26.10, 31.97, 33.03, 41.96, 47.83, 76.20, 102.9,
125.6, 136.7, 166.7 ppm (peak assignment of main isomers)
Monomer Synthesis Example 4
Synthesis of 2-oxaspiro[5,5]undecan-1-yl methacrylate
Monomer Synthesis Example 4-1
Synthesis of 2-oxaspiro[5,5]undecan-1-ol
##STR00068##
[0215] To a mixture of 44 g of ethylmagnesium bromide and 120 g of
tetrahydrofuran was added a mixture of 50 g of
cyclohexylmethylenecyclohexylamine and 50 g of tetrahydrofuran. The
resulting mixture was stirred for 2 hours under tetrahydrofuran
reflux conditions. Thereafter, 21 g of oxetane was added under ice
cooling to the reaction mixture, which was stirred for a further 20
hours at room temperature. Then 30 g of acetic acid was added to
quench the reaction, followed by ordinary aqueous workup, obtaining
67 g of a crude product,
1-[(1-cyclohexyliminomethyl)cyclo-hexyl]propan-1-ol. To 67 g of the
crude product were added 16 g of acetic acid, 400 g of hexane, and
280 g of water. The mixture was stirred at 50.degree. C. for 12
hours. The reaction mixture was then subjected to ordinary aqueous
workup and distillation for purification, obtaining 22 g (yield
50%) of the target compound, 2-oxaspiro[5,5]undecan-1-ol.
Monomer Synthesis Example 4-2
Synthesis of 2-oxaspiro[5,5]undecan-1-yl acetate
##STR00069##
[0217] A mixture of 22 g of 2-oxaspiro[5,5]undecan-1-ol, 15 g of
pyridine and 19 g of acetic anhydride was heated at 50.degree. C.
for 12 hours. The reaction mixture was concentrated. The
concentrate was purified by distillation, obtaining 25 g (yield
91%) of the target compound, 2-oxaspiro[5,5]undecan-1-yl
acetate.
Monomer Synthesis Example 4-3
Synthesis of 2-oxaspiro[5,5]undecan-1-yl methacrylate
##STR00070##
[0219] A mixture of 25 g of 2-oxaspiro[5,5]undecan-1-yl acetate, 50
g of methacrylic acid, and 25 mg of
2,2'-methylenebis(6-t-butyl-p-cresol) was heated at 50.degree. C.
under atmospheric pressure for 30 minutes, after which under a
reduced pressure of 0.20 kPa, the reaction mixture was heated for
18 hours for distilling off the acetic acid formed. The reaction
mixture was purified by distillation, obtaining 21 g (yield 74%) of
the target compound, 2-oxaspiro[5,5]undecan-1-yl methacrylate.
Monomer Synthesis Example 5
Synthesis of 4-oxatricyclo[4.2.1.0.sup.3,7]non-5-yl
methacrylate
Monomer Synthesis Example 5-1
Synthesis of 4-oxatricyclo[4.2.1.0.sup.3,7]non-5-yl acetate
##STR00071##
[0221] A mixture of 14 g of
4-oxatricyclo[4.2.1.0.sup.3,7]nonan-5-ol, 12 g of pyridine and 14 g
of acetic anhydride was heated at 50.degree. C. for 5 hours. The
reaction mixture was concentrated. The concentrate was purified by
distillation, obtaining 16 g (yield 88%) of the target
compound.
Monomer Synthesis Example 5-2
Synthesis of 4-oxatricyclo[4.2.1.0.sup.3,7]non-5-yl
methacrylate
##STR00072##
[0223] A mixture of 16 g of 4-oxatricyclo[4.2.1.0.sup.3,7]non-5-yl
acetate, 40 g of methacrylic acid, and 16 mg of
2,2'-methylenebis(6-t-butyl-p-cresol) was heated at 50.degree. C.
under atmospheric pressure for 30 minutes, after which under a
reduced pressure of 0.20 kPa, the reaction mixture was heated for
18 hours for distilling off the acetic acid formed. The reaction
mixture was purified by distillation, obtaining 17 g (yield 91%) of
the target compound.
Polymer Synthesis Examples
[0224] Polymers were synthesized in accordance with the following
formulation.
Polymer Synthesis Example 1
Synthesis of Polymer P-01
[0225] In a nitrogen blanket, a flask was charged with 8.19 g of
3-methyl-2-oxaspiro[4,5]decan-1-yl methacrylate, 5.07 g of
3-hydroxy-1-adamantyl methacrylate, 6.74 g of
4,8-dioxatricyclo[4.2.1.0.sup.3,7]nonan-5-on-2-yl methacrylate, 989
mg of 2,2'-azobis(2-methylpropionic acid)dimethyl (MAIB), and 35.0
g of methyl ethyl ketone (MEK) to form a monomer solution. Another
flask in a nitrogen blanket was charged with 11.7 g of MEK, which
was heated up to 80.degree. C. while stirring. The monomer solution
was added dropwise to the hot MEK over 4 hours. After the
completion of dropwise addition, the polymerization solution was
continuously stirred for 2 hours while keeping the solution
temperature at 80.degree. C. The polymerization solution was cooled
to room temperature and then added dropwise to 200 g of hexane,
with vigorous stirring. The thus precipitated copolymer was
filtered. The copolymer was washed twice with a solvent mixture of
22.7 g of MEK and 97.3 g of hexane, and vacuum dried at 50.degree.
C. for 20 hours, obtaining the copolymer in white powder form. The
copolymer had a weight average molecular weight (Mw) of 9,000 as
measured by gel permeation chromatography (GPC) versus polystyrene
standards, and a dispersity (Mw/Mn) of 2.35.
Polymer Synthesis Examples 2 to 24
Synthesis of Polymers P-02 to P-24
[0226] Polymers P-02 to P-24 were synthesized by the same procedure
as above or a well-known procedure.
Comparative Polymer Synthesis Examples 1 to 6
Synthesis of Polymers P-25 to P-30
[0227] Polymers P-25 to P-30 were synthesized by the same procedure
as above or a well-known procedure.
Resist Preparation Examples
[0228] Resist compositions were formulated using the inventive and
comparative polymers as a base resin and examined for resist
properties.
Resist Preparation Examples 1 to 24 & Comparative Resist
Preparation Examples 1 to 6
[0229] Resist compositions were prepared by dissolving the
inventive polymers (P-01 to P-24), a photoacid generator (PAG), and
a basic compound in a solvent in accordance with the formulation
shown in Table 1. These compositions were filtered through a
Teflon.RTM. filter with a pore diameter of 0.2 .mu.m, thereby
giving resist solutions (R-01 to R-24). In all runs, the solvent
contained 0.01% by weight of surfactant KH-20 (Asahi Glass Co.,
Ltd.). Comparative resist compositions (R-25 to R-30) were
similarly prepared in accordance with the formulation shown in
Table 2.
TABLE-US-00001 TABLE 1 Resist Resin PAG Base Solvent 1 Solvent 2
R-01 P-01 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-02 P-02 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-03 P-03 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-04 P-04 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-05 P-05 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-06 P-06 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-07 P-07 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-08 P-08 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-09 P-09 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-10 P-10 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-11 P-11 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-12 P-12 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-13 P-13 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-14 P-14 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-15 P-15 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-16 P-16 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-17 P-17 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-18 P-18 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-19 P-19 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-20 P-20 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-21 P-21 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-22 P-22 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-23 P-23 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-24 P-24 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
TABLE-US-00002 TABLE 2 Resist Resin PAG Base Solvent 1 Solvent 2
R-25 P-25 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-26 P-26 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-27 P-27 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-28 P-28 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-29 P-29 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
R-30 P-30 (80) PAG-1 (4.4) Base-1 (0.94) PGMEA (560) CyHO (240)
[0230] In Tables 1 and 2, the values in parentheses are in parts by
weight. The acid generator, base and solvent are designated by
abbreviations, which have the following meaning.
PAG-1: triphenylsulfonium nonafluorobutanesulfonate
Base-1: tri(2-methoxymethoxyethyl)amine
PGMEA: 1-methoxyisopropyl acetate
CyHO: cyclohexanone
[0231] The resins designated by abbreviations are polymers
constructed as in Tables 3 to 6.
TABLE-US-00003 TABLE 3 Resin Unit 1 Unit 2 Unit 3 Unit 4 Mw P-01
A-1M (0.30) B-1M (0.25) B-2M (0.45) 7,200 P-02 A-1M (0.40) B-1M
(0.25) B-2M (0.35) 7,600 P-03 A-2M (0.30) B-1M (0.25) B-2M (0.45)
6,500 P-04 A-2M (0.40) B-1M (0.25) B-2M (0.35) 7,800 P-05 A-3M
(0.30) B-1M (0.25) B-2M (0.45) 7,500 P-06 A-3M (0.40) B-1M (0.25)
B-2M (0.35) 6,600 P-07 A-4M (0.30) B-1M (0.25) B-2M (0.45) 6,800
P-08 A-4M (0.40) B-1M (0.25) B-2M (0.35) 6,300 P-09 A-4M (0.35)
B-1M (0.30) B-2M (0.35) 6,200 P-10 A-1M (0.30) A-5M (0.20) B-1M
(0.25) B-2M (0.25) 6,500 P-11 A-2M (0.30) A-5M (0.20) B-1M (0.25)
B-2M (0.25) 7,700 P-12 A-3M (0.30) A-5M (0.20) B-1M (0.25) B-2M
(0.25) 6,400 P-13 A-4M (0.30) A-5M (0.20) B-1M (0.25) B-2M (0.25)
6,200 P-14 A-1M (0.30) A-6M (0.20) B-1M (0.25) B-2M (0.25) 7,700
P-15 A-2M (0.30) A-6M (0.20) B-1M (0.25) B-2M (0.25) 7,800 P-16
A-3M (0.30) A-6M (0.20) B-1M (0.25) B-2M (0.25) 7,500 P-17 A-4M
(0.30) A-6M (0.20) B-1M (0.25) B-2M (0.25) 6,000 P-18 A-1M (0.30)
B-1M (0.25) B-2M (0.35) B-6M (0.10) 6,100 P-19 A-1M (0.30) B-1M
(0.25) B-2M (0.35) F-1M (0.10) 6,300 P-20 A-1M (0.30) B-1M (0.25)
B-2M (0.35) F-2M (0.10) 6,500 P-21 A-1M (0.25) B-1M (0.25) B-2M
(0.35) F-3M (0.10) 6,200 P-22 A-1M (0.30) B-1M (0.25) B-3M (0.45)
6,400 P-23 A-1M (0.30) B-1M (0.25) B-4M (0.45) 6,000 P-24 A-12C
(0.25) A-13C A-14C 6,000 (0.25) (0.50) P-25 A-6M (0.30) B-1M (0.25)
B-2M (0.45) 6,000 P-26 A-7M (0.30) B-1M (0.25) B-2M (0.45) 6,000
P-27 A-8M (0.30) B-1M (0.25) B-2M (0.45) 6,000 P-28 A-9M (0.30)
B-1M (0.25) B-2M (0.45) 6,000 P-29 A-10M (0.30) B-1M (0.25) B-2M
(0.45) 6,000 P-30 A-11M (0.30) B-1M (0.25) B-2M (0.45) 6,000 The
value in parentheses is an incorporation ratio of a particular unit
expressed in molar ratio.
TABLE-US-00004 TABLE 4 ##STR00073## ##STR00074## ##STR00075##
##STR00076## ##STR00077## ##STR00078## ##STR00079## ##STR00080##
##STR00081## ##STR00082## ##STR00083## ##STR00084## ##STR00085##
##STR00086##
TABLE-US-00005 TABLE 5 ##STR00087## ##STR00088## ##STR00089##
##STR00090## ##STR00091## ##STR00092##
TABLE-US-00006 TABLE 6 ##STR00093## ##STR00094## ##STR00095##
##STR00096##
Examples 1 to 24
[0232] On silicon wafers having an antireflective coating (ARC29A,
Nissan Chemical Industries Ltd.) of 78 nm thick, the resist
solutions (R-01 to 24) of the invention were spin coated, then
baked at 110.degree. C. for 60 seconds to give resist films having
a thickness of 170 nm. Using an ArF excimer laser stepper (Nikon
Corp., NA 0.68), the resist films were exposed, baked (PEB) for 60
seconds and then puddle developed for 30 seconds with a 2.38 wt %
aqueous solution of tetramethylammonium hydroxide. In this way, 1:1
line-and-space patterns were formed. The PEB step used an optimum
temperature for a particular resist composition.
Test 1: Evaluation of Resolution
[0233] The pattern-bearing wafers were observed under a top-down
scanning electron microscope (TDSEM). The optimum exposure was an
exposure dose (mJ/cm.sup.2) which provided a 1:1 resolution at the
top and bottom of a 0.11-.mu.m 1:1 line-and-space pattern. The
maximum resolution of the resist was defined as the minimum line
width (in increments of 0.01 Mm) of a 1:1 line-and-space pattern
that separated at the optimum exposure, with smaller values
indicating better resolution.
[0234] Table 7 tabulates the test results (maximum resolution) of
the resist compositions.
TABLE-US-00007 TABLE 7 Optimum Maximum Test run Resist PEB temp.
exposure resolution Pattern profile 1-1 R-01 125.degree. C. 42.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-2 R-02 125.degree. C. 39.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-3 R-03 115.degree. C. 41.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-4 R-04 110.degree. C. 42.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-5 R-05 120.degree. C. 44.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-6 R-06 110.degree. C. 45.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-7 R-07 110.degree. C. 45.0
mJ/cm.sup.2 0.10 .mu.m rectangular 1-8 R-08 115.degree. C. 42.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-9 R-09 115.degree. C. 39.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-10 R-10 120.degree. C. 43.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-11 R-11 110.degree. C. 40.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-12 R-12 110.degree. C. 38.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-13 R-13 110.degree. C. 44.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-14 R-14 110.degree. C. 41.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-15 R-15 110.degree. C. 42.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-16 R-16 110.degree. C. 37.0
mJ/cm.sup.2 0.10 .mu.m rectangular 1-17 R-17 110.degree. C. 45.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-18 R-18 110.degree. C. 44.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-19 R-19 105.degree. C. 40.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-20 R-20 110.degree. C. 42.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-21 R-21 105.degree. C. 40.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-22 R-22 110.degree. C. 41.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-23 R-23 110.degree. C. 44.0
mJ/cm.sup.2 0.09 .mu.m rectangular 1-24 R-24 120.degree. C. 45.0
mJ/cm.sup.2 0.09 .mu.m rectangular
[0235] The data of Table 7 demonstrate that the resist compositions
within the scope of the invention have a high resolution.
Test 2: Evaluation of Outgassing
[0236] On silicon wafers having an antireflective coating (ARC29A,
Nissan Chemical Industries Ltd.) of 78 nm thick, the resist
solutions (R-01 to 24) of the invention and the comparative resist
solutions (R-29 and R-30) were spin coated, then baked at
110.degree. C. for 60 seconds to give resist films having a
thickness of 170 nm. Using an ArF excimer laser scanner S305B
(Nikon Corp., NA 0.60), the resist films were subjected to
open-frame exposure at a stepwise varying exposure dose, after
which the thickness of the film was measured. A percent film
thickness reduction is calculated and recorded as [(initial
thickness)-(thickness after exposure)]/(initial thickness).
[0237] Thereafter, the resist films were heated at 110.degree. C.
for 90 seconds, puddle developed for 30 seconds with a 2.38 wt %
aqueous solution of tetramethylammonium hydroxide, washed with
deionized water for 30 seconds, and spin dried. Herein, Eth is
defined as the exposure dose at which the resist film is resolved
to the bottom. A percent film thickness reduction resulting from an
exposure dose which is 3 times Eth is an index of outgassing. A
smaller value indicates a less quantity of outgas and hence, a
better property. Tables 8 and 9 tabulate the test results of
inventive and comparative resist compositions, respectively.
TABLE-US-00008 TABLE 8 Test run Resist Outgas index (%) 2-1 R-01
2.1 2-2 R-02 2.3 2-3 R-03 1.7 2-4 R-04 1.9 2-5 R-05 1.5 2-6 R-06
2.0 2-7 R-07 2.0 2-8 R-08 1.5 2-9 R-09 2.1 2-10 R-10 1.9 2-11 R-11
2.2 2-12 R-12 1.6 2-13 R-13 1.8 2-14 R-14 1.7 2-15 R-15 2.1 2-16
R-16 2.3 2-17 R-17 2.5 2-18 R-18 1.6 2-19 R-19 1.7 2-20 R-20 1.9
2-21 R-21 1.5 2-22 R-22 1.8 2-23 R-23 2.0 2-24 R-24 2.3
TABLE-US-00009 TABLE 9 Test run Resist Outgas index (%) 2-25 R-29
5.2 2-26 R-30 9.8
[0238] It is demonstrated that the resist films using the resist
compositions of the invention are minimized in outgassing.
[0239] Japanese Patent Application No. 2006-186298 is incorporated
herein by reference.
[0240] Although some preferred embodiments have been described,
many modifications and variations may be made thereto in light of
the above teachings. It is therefore to be understood that the
invention may be practiced otherwise than as specifically described
without departing from the scope of the appended claims.
* * * * *